diff --git a/content/smil/nsSMILAnimationController.cpp b/content/smil/nsSMILAnimationController.cpp
index d486dd973b4d..eaea65e91bae 100644
--- a/content/smil/nsSMILAnimationController.cpp
+++ b/content/smil/nsSMILAnimationController.cpp
@@ -213,7 +213,7 @@ nsSMILAnimationController::Traverse(
   }
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::CompositorTableEntryTraverse(
                                       nsSMILCompositor* aCompositor,
                                       void* aArg)
@@ -303,7 +303,7 @@ nsSMILAnimationController::MaybeStartSampling(nsRefreshDriver* aRefreshDriver)
 //----------------------------------------------------------------------
 // Sample-related methods and callbacks
 
-PR_CALLBACK PLDHashOperator
+PLDHashOperator
 TransferCachedBaseValue(nsSMILCompositor* aCompositor,
                         void* aData)
 {
@@ -319,7 +319,7 @@ TransferCachedBaseValue(nsSMILCompositor* aCompositor,
   return PL_DHASH_NEXT;  
 }
 
-PR_CALLBACK PLDHashOperator
+PLDHashOperator
 RemoveCompositorFromTable(nsSMILCompositor* aCompositor,
                           void* aData)
 {
@@ -329,7 +329,7 @@ RemoveCompositorFromTable(nsSMILCompositor* aCompositor,
   return PL_DHASH_NEXT;
 }
 
-PR_CALLBACK PLDHashOperator
+PLDHashOperator
 DoClearAnimationEffects(nsSMILCompositor* aCompositor,
                         void* /*aData*/)
 {
@@ -337,7 +337,7 @@ DoClearAnimationEffects(nsSMILCompositor* aCompositor,
   return PL_DHASH_NEXT;
 }
 
-PR_CALLBACK PLDHashOperator
+PLDHashOperator
 DoComposeAttribute(nsSMILCompositor* aCompositor,
                    void* /*aData*/)
 {
@@ -467,7 +467,7 @@ nsSMILAnimationController::RewindElements()
   mChildContainerTable.EnumerateEntries(ClearRewindNeeded, nullptr);
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::RewindNeeded(TimeContainerPtrKey* aKey,
                                         void* aData)
 {
@@ -484,7 +484,7 @@ nsSMILAnimationController::RewindNeeded(TimeContainerPtrKey* aKey,
   return PL_DHASH_NEXT;
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::RewindAnimation(AnimationElementPtrKey* aKey,
                                            void* aData)
 {
@@ -497,7 +497,7 @@ nsSMILAnimationController::RewindAnimation(AnimationElementPtrKey* aKey,
   return PL_DHASH_NEXT;
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::ClearRewindNeeded(TimeContainerPtrKey* aKey,
                                              void* aData)
 {
@@ -582,7 +582,7 @@ nsSMILAnimationController::DoMilestoneSamples()
   }
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::GetNextMilestone(TimeContainerPtrKey* aKey,
                                             void* aData)
 {
@@ -607,7 +607,7 @@ nsSMILAnimationController::GetNextMilestone(TimeContainerPtrKey* aKey,
   return PL_DHASH_NEXT;
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::GetMilestoneElements(TimeContainerPtrKey* aKey,
                                                 void* aData)
 {
@@ -629,7 +629,7 @@ nsSMILAnimationController::GetMilestoneElements(TimeContainerPtrKey* aKey,
   return PL_DHASH_NEXT;
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::SampleTimeContainer(TimeContainerPtrKey* aKey,
                                                void* aData)
 {
@@ -652,7 +652,7 @@ nsSMILAnimationController::SampleTimeContainer(TimeContainerPtrKey* aKey,
   return PL_DHASH_NEXT;
 }
 
-/*static*/ PR_CALLBACK PLDHashOperator
+/*static*/ PLDHashOperator
 nsSMILAnimationController::SampleAnimation(AnimationElementPtrKey* aKey,
                                            void* aData)
 {
diff --git a/content/smil/nsSMILTimedElement.cpp b/content/smil/nsSMILTimedElement.cpp
index 0619e91be9d9..85e387584e59 100644
--- a/content/smil/nsSMILTimedElement.cpp
+++ b/content/smil/nsSMILTimedElement.cpp
@@ -2318,7 +2318,7 @@ nsSMILTimedElement::AreEndTimesDependentOn(
 //----------------------------------------------------------------------
 // Hashtable callback functions
 
-/* static */ PR_CALLBACK PLDHashOperator
+/* static */ PLDHashOperator
 nsSMILTimedElement::NotifyNewIntervalCallback(TimeValueSpecPtrKey* aKey,
                                               void* aData)
 {
diff --git a/gfx/thebes/gfxPlatformFontList.cpp b/gfx/thebes/gfxPlatformFontList.cpp
index 66dfb5a1caed..e5b512b0fc43 100644
--- a/gfx/thebes/gfxPlatformFontList.cpp
+++ b/gfx/thebes/gfxPlatformFontList.cpp
@@ -207,7 +207,7 @@ gfxPlatformFontList::InitOtherFamilyNames()
     mFontFamilies.Enumerate(gfxPlatformFontList::InitOtherFamilyNamesProc, this);
 }
                                                          
-PLDHashOperator PR_CALLBACK
+PLDHashOperator
 gfxPlatformFontList::InitOtherFamilyNamesProc(nsStringHashKey::KeyType aKey,
                                               nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                               void* userArg)
@@ -227,7 +227,7 @@ gfxPlatformFontList::InitFaceNameLists()
     mFontFamilies.Enumerate(gfxPlatformFontList::InitFaceNameListsProc, this);
 }
 
-PLDHashOperator PR_CALLBACK
+PLDHashOperator
 gfxPlatformFontList::InitFaceNameListsProc(nsStringHashKey::KeyType aKey,
                                            nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                            void* userArg)
@@ -308,7 +308,7 @@ struct FontListData {
     nsTArray<nsString>& mListOfFonts;
 };
 
-PLDHashOperator PR_CALLBACK
+PLDHashOperator
 gfxPlatformFontList::HashEnumFuncForFamilies(nsStringHashKey::KeyType aKey,
                                              nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                              void *aUserArg)
@@ -358,9 +358,9 @@ struct FontFamilyListData {
         : mFamilyArray(aFamilyArray)
     {}
 
-    static PLDHashOperator PR_CALLBACK AppendFamily(nsStringHashKey::KeyType aKey,
-                                                    nsRefPtr<gfxFontFamily>& aFamilyEntry,
-                                                    void *aUserArg)
+    static PLDHashOperator AppendFamily(nsStringHashKey::KeyType aKey,
+                                        nsRefPtr<gfxFontFamily>& aFamilyEntry,
+                                        void *aUserArg)
     {
         FontFamilyListData *data = static_cast<FontFamilyListData*>(aUserArg);
         data->mFamilyArray.AppendElement(aFamilyEntry);
@@ -461,7 +461,7 @@ gfxPlatformFontList::SystemFindFontForChar(const uint32_t aCh,
     return fontEntry;
 }
 
-PLDHashOperator PR_CALLBACK 
+PLDHashOperator 
 gfxPlatformFontList::FindFontForCharProc(nsStringHashKey::KeyType aKey, nsRefPtr<gfxFontFamily>& aFamilyEntry,
      void *userArg)
 {
diff --git a/modules/libpref/public/Preferences.h b/modules/libpref/public/Preferences.h
index 802ed5f23cb2..6fcc48ef3b89 100644
--- a/modules/libpref/public/Preferences.h
+++ b/modules/libpref/public/Preferences.h
@@ -25,7 +25,7 @@ class nsAdoptingString;
 class nsAdoptingCString;
 
 #ifndef have_PrefChangedFunc_typedef
-typedef int (*PR_CALLBACK PrefChangedFunc)(const char *, void *);
+typedef int (*PrefChangedFunc)(const char *, void *);
 #define have_PrefChangedFunc_typedef
 #endif
 
diff --git a/security/manager/ssl/src/nsCertOverrideService.h b/security/manager/ssl/src/nsCertOverrideService.h
index 99a1bde824fc..1e13829d3edd 100644
--- a/security/manager/ssl/src/nsCertOverrideService.h
+++ b/security/manager/ssl/src/nsCertOverrideService.h
@@ -142,8 +142,8 @@ public:
   void RemoveAllTemporaryOverrides();
 
   typedef void 
-  (*PR_CALLBACK CertOverrideEnumerator)(const nsCertOverride &aSettings,
-                                        void *aUserData);
+  (*CertOverrideEnumerator)(const nsCertOverride &aSettings,
+                            void *aUserData);
 
   // aCert == null: return all overrides
   // aCert != null: return overrides that match the given cert
diff --git a/security/manager/ssl/src/nsCrypto.cpp b/security/manager/ssl/src/nsCrypto.cpp
index 84ec7a4f8e5c..8e0aa439d08d 100644
--- a/security/manager/ssl/src/nsCrypto.cpp
+++ b/security/manager/ssl/src/nsCrypto.cpp
@@ -1469,10 +1469,10 @@ nsSetKeyEnciphermentPOP(CRMFCertReqMsg *certReqMsg, bool isEscrowed)
   return (srv == SECSuccess) ? NS_OK : NS_ERROR_FAILURE;
 }
 
-static void PR_CALLBACK
+static void
 nsCRMFEncoderItemCount(void *arg, const char *buf, unsigned long len);
 
-static void PR_CALLBACK
+static void
 nsCRMFEncoderItemStore(void *arg, const char *buf, unsigned long len);
 
 static nsresult
@@ -1733,14 +1733,14 @@ nsSetProofOfPossession(CRMFCertReqMsg *certReqMsg,
   return nsSet_EC_DHMAC_ProofOfPossession(certReqMsg, keyInfo, certReq);
 }
 
-static void PR_CALLBACK
+static void
 nsCRMFEncoderItemCount(void *arg, const char *buf, unsigned long len)
 {
   unsigned long *count = (unsigned long *)arg;
   *count += len;
 }
 
-static void PR_CALLBACK
+static void
 nsCRMFEncoderItemStore(void *arg, const char *buf, unsigned long len)
 {
   SECItem *dest = (SECItem *)arg;
diff --git a/security/manager/ssl/src/nsIdentityChecking.cpp b/security/manager/ssl/src/nsIdentityChecking.cpp
index a5280ba3e783..7905b590ac9c 100644
--- a/security/manager/ssl/src/nsIdentityChecking.cpp
+++ b/security/manager/ssl/src/nsIdentityChecking.cpp
@@ -954,7 +954,7 @@ isApprovedForEV(SECOidTag policyOIDTag, CERTCertificate *rootCert)
   return false;
 }
 
-PRStatus PR_CALLBACK
+PRStatus
 nsNSSComponent::IdentityInfoInit()
 {
   for (size_t iEV=0; iEV < (sizeof(myTrustedEVInfos)/sizeof(nsMyTrustedEVInfo)); ++iEV) {
diff --git a/security/manager/ssl/src/nsKeygenThread.cpp b/security/manager/ssl/src/nsKeygenThread.cpp
index 6c50a8877a3a..8bd247578ac8 100644
--- a/security/manager/ssl/src/nsKeygenThread.cpp
+++ b/security/manager/ssl/src/nsKeygenThread.cpp
@@ -111,7 +111,7 @@ nsresult nsKeygenThread::ConsumeResult(
   return rv;
 }
 
-static void PR_CALLBACK nsKeygenThreadRunner(void *arg)
+static void nsKeygenThreadRunner(void *arg)
 {
   PR_SetCurrentThreadName("Keygen");
   nsKeygenThread *self = static_cast<nsKeygenThread *>(arg);
diff --git a/security/manager/ssl/src/nsNSSCallbacks.cpp b/security/manager/ssl/src/nsNSSCallbacks.cpp
index 97d1cf1beac6..2489b0b4584a 100644
--- a/security/manager/ssl/src/nsNSSCallbacks.cpp
+++ b/security/manager/ssl/src/nsNSSCallbacks.cpp
@@ -771,7 +771,7 @@ void PK11PasswordPromptRunnable::RunOnTargetThread()
   }
 }
 
-char* PR_CALLBACK
+char*
 PK11PasswordPrompt(PK11SlotInfo* slot, PRBool retry, void* arg)
 {
   nsRefPtr<PK11PasswordPromptRunnable> runnable = 
@@ -781,7 +781,7 @@ PK11PasswordPrompt(PK11SlotInfo* slot, PRBool retry, void* arg)
   return runnable->mResult;
 }
 
-void PR_CALLBACK HandshakeCallback(PRFileDesc* fd, void* client_data) {
+void HandshakeCallback(PRFileDesc* fd, void* client_data) {
   nsNSSShutDownPreventionLock locker;
   int32_t sslStatus;
   char* signer = nullptr;
@@ -1026,7 +1026,7 @@ static CERT_StringFromCertFcn oldOCSPAIAInfoCallback = nullptr;
  *
  * The result needs to be freed (PORT_Free) when no longer in use.
  */
-char* PR_CALLBACK MyAlternateOCSPAIAInfoCallback(CERTCertificate *cert) {
+char* MyAlternateOCSPAIAInfoCallback(CERTCertificate *cert) {
   if (cert && !cert->isRoot) {
     unsigned int i;
     for (i=0; i < numResponders; i++) {
diff --git a/security/manager/ssl/src/nsNSSCallbacks.h b/security/manager/ssl/src/nsNSSCallbacks.h
index a3a39eaf6ffc..08d0c6ddd996 100644
--- a/security/manager/ssl/src/nsNSSCallbacks.h
+++ b/security/manager/ssl/src/nsNSSCallbacks.h
@@ -15,10 +15,10 @@
 #include "mozilla/Mutex.h"
 #include "mozilla/Attributes.h"
 
-char* PR_CALLBACK
+char*
 PK11PasswordPrompt(PK11SlotInfo *slot, PRBool retry, void* arg);
 
-void PR_CALLBACK HandshakeCallback(PRFileDesc *fd, void *client_data);
+void HandshakeCallback(PRFileDesc *fd, void *client_data);
 
 SECStatus RegisterMyOCSPAIAInfoCallback();
 SECStatus UnregisterMyOCSPAIAInfoCallback();
diff --git a/security/manager/ssl/src/nsNSSCertificateDB.cpp b/security/manager/ssl/src/nsNSSCertificateDB.cpp
index 7b60487db8fb..a85becba0ff6 100644
--- a/security/manager/ssl/src/nsNSSCertificateDB.cpp
+++ b/security/manager/ssl/src/nsNSSCertificateDB.cpp
@@ -190,7 +190,7 @@ cleanup:
   return rv;
 }
 
-SECStatus PR_CALLBACK
+SECStatus
 collect_certs(void *arg, SECItem **certs, int numcerts)
 {
   CERTDERCerts *collectArgs;
@@ -1209,7 +1209,7 @@ nsNSSCertificateDB::ExportPKCS12File(nsISupports     *aToken,
 }
 
 
-static SECStatus PR_CALLBACK 
+static SECStatus 
 GetOCSPResponders (CERTCertificate *aCert,
                    SECItem         *aDBKey,
                    void            *aArg)
diff --git a/security/manager/ssl/src/nsNSSComponent.cpp b/security/manager/ssl/src/nsNSSComponent.cpp
index f267f6ba03ea..688e261e7597 100644
--- a/security/manager/ssl/src/nsNSSComponent.cpp
+++ b/security/manager/ssl/src/nsNSSComponent.cpp
@@ -97,13 +97,12 @@ int nsNSSComponent::mInstanceCount = 0;
 bool nsNSSComponent::globalConstFlagUsePKIXVerification = false;
 
 // XXX tmp callback for slot password
-extern char * PR_CALLBACK 
-pk11PasswordPrompt(PK11SlotInfo *slot, PRBool retry, void *arg);
+extern char* pk11PasswordPrompt(PK11SlotInfo *slot, PRBool retry, void *arg);
 
 #define PIPNSS_STRBUNDLE_URL "chrome://pipnss/locale/pipnss.properties"
 #define NSSERR_STRBUNDLE_URL "chrome://pipnss/locale/nsserrors.properties"
 
-static PLHashNumber PR_CALLBACK certHashtable_keyHash(const void *key)
+static PLHashNumber certHashtable_keyHash(const void *key)
 {
   if (!key)
     return 0;
@@ -123,7 +122,7 @@ static PLHashNumber PR_CALLBACK certHashtable_keyHash(const void *key)
   return hash;
 }
 
-static int PR_CALLBACK certHashtable_keyCompare(const void *k1, const void *k2)
+static int certHashtable_keyCompare(const void *k1, const void *k2)
 {
   // return type is a bool, answering the question "are the keys equal?"
 
@@ -150,7 +149,7 @@ static int PR_CALLBACK certHashtable_keyCompare(const void *k1, const void *k2)
   return true;
 }
 
-static int PR_CALLBACK certHashtable_valueCompare(const void *v1, const void *v2)
+static int certHashtable_valueCompare(const void *v1, const void *v2)
 {
   // two values are identical if their keys are identical
   
@@ -163,7 +162,7 @@ static int PR_CALLBACK certHashtable_valueCompare(const void *v1, const void *v2
   return certHashtable_keyCompare(&cert1->certKey, &cert2->certKey);
 }
 
-static int PR_CALLBACK certHashtable_clearEntry(PLHashEntry *he, int /*index*/, void * /*userdata*/)
+static int certHashtable_clearEntry(PLHashEntry *he, int /*index*/, void * /*userdata*/)
 {
   if (he && he->value) {
     CERT_DestroyCertificate((CERTCertificate*)he->value);
diff --git a/security/manager/ssl/src/nsNSSComponent.h b/security/manager/ssl/src/nsNSSComponent.h
index fcc10c07aac1..efa83c2c431b 100644
--- a/security/manager/ssl/src/nsNSSComponent.h
+++ b/security/manager/ssl/src/nsNSSComponent.h
@@ -326,7 +326,7 @@ private:
   nsRefPtr<nsCERTValInParamWrapper> mDefaultCERTValInParam;
   nsRefPtr<nsCERTValInParamWrapper> mDefaultCERTValInParamLocalOnly;
 
-  static PRStatus PR_CALLBACK IdentityInfoInit(void);
+  static PRStatus IdentityInfoInit(void);
   PRCallOnceType mIdentityInfoCallOnce;
 
 public:
diff --git a/security/manager/ssl/src/nsNSSIOLayer.cpp b/security/manager/ssl/src/nsNSSIOLayer.cpp
index f55785d45d41..4f6dd0ee9776 100644
--- a/security/manager/ssl/src/nsNSSIOLayer.cpp
+++ b/security/manager/ssl/src/nsNSSIOLayer.cpp
@@ -592,7 +592,7 @@ getSocketInfoIfRunning(PRFileDesc * fd, Operation op,
 
 } // unnnamed namespace
 
-static PRStatus PR_CALLBACK
+static PRStatus
 nsSSLIOLayerConnect(PRFileDesc* fd, const PRNetAddr* addr,
                     PRIntervalTime timeout)
 {
@@ -667,7 +667,7 @@ nsSSLIOLayerHelpers::rememberTolerantSite(nsNSSSocketInfo *socketInfo)
   nsSSLIOLayerHelpers::mTLSTolerantSites->PutEntry(key);
 }
 
-static PRStatus PR_CALLBACK
+static PRStatus
 nsSSLIOLayerClose(PRFileDesc *fd)
 {
   nsNSSShutDownPreventionLock locker;
@@ -947,7 +947,7 @@ int32_t checkHandshake(int32_t bytesTransfered, bool wasReading,
 
 }
 
-static int16_t PR_CALLBACK
+static int16_t
 nsSSLIOLayerPoll(PRFileDesc * fd, int16_t in_flags, int16_t *out_flags)
 {
   nsNSSShutDownPreventionLock locker;
@@ -1045,7 +1045,7 @@ static PRFileDesc *_PSM_InvalidDesc(void)
     return NULL;
 }
 
-static PRStatus PR_CALLBACK PSMGetsockname(PRFileDesc *fd, PRNetAddr *addr)
+static PRStatus PSMGetsockname(PRFileDesc *fd, PRNetAddr *addr)
 {
   nsNSSShutDownPreventionLock locker;
   if (!getSocketInfoIfRunning(fd, not_reading_or_writing, locker))
@@ -1054,7 +1054,7 @@ static PRStatus PR_CALLBACK PSMGetsockname(PRFileDesc *fd, PRNetAddr *addr)
   return fd->lower->methods->getsockname(fd->lower, addr);
 }
 
-static PRStatus PR_CALLBACK PSMGetpeername(PRFileDesc *fd, PRNetAddr *addr)
+static PRStatus PSMGetpeername(PRFileDesc *fd, PRNetAddr *addr)
 {
   nsNSSShutDownPreventionLock locker;
   if (!getSocketInfoIfRunning(fd, not_reading_or_writing, locker))
@@ -1063,8 +1063,7 @@ static PRStatus PR_CALLBACK PSMGetpeername(PRFileDesc *fd, PRNetAddr *addr)
   return fd->lower->methods->getpeername(fd->lower, addr);
 }
 
-static PRStatus PR_CALLBACK PSMGetsocketoption(PRFileDesc *fd, 
-                                        PRSocketOptionData *data)
+static PRStatus PSMGetsocketoption(PRFileDesc *fd, PRSocketOptionData *data)
 {
   nsNSSShutDownPreventionLock locker;
   if (!getSocketInfoIfRunning(fd, not_reading_or_writing, locker))
@@ -1073,8 +1072,8 @@ static PRStatus PR_CALLBACK PSMGetsocketoption(PRFileDesc *fd,
   return fd->lower->methods->getsocketoption(fd, data);
 }
 
-static PRStatus PR_CALLBACK PSMSetsocketoption(PRFileDesc *fd, 
-                                        const PRSocketOptionData *data)
+static PRStatus PSMSetsocketoption(PRFileDesc *fd,
+                                   const PRSocketOptionData *data)
 {
   nsNSSShutDownPreventionLock locker;
   if (!getSocketInfoIfRunning(fd, not_reading_or_writing, locker))
@@ -1083,7 +1082,7 @@ static PRStatus PR_CALLBACK PSMSetsocketoption(PRFileDesc *fd,
   return fd->lower->methods->setsocketoption(fd, data);
 }
 
-static int32_t PR_CALLBACK PSMRecv(PRFileDesc *fd, void *buf, int32_t amount,
+static int32_t PSMRecv(PRFileDesc *fd, void *buf, int32_t amount,
     int flags, PRIntervalTime timeout)
 {
   nsNSSShutDownPreventionLock locker;
@@ -1108,7 +1107,7 @@ static int32_t PR_CALLBACK PSMRecv(PRFileDesc *fd, void *buf, int32_t amount,
   return checkHandshake(bytesRead, true, fd, socketInfo);
 }
 
-static int32_t PR_CALLBACK PSMSend(PRFileDesc *fd, const void *buf, int32_t amount,
+static int32_t PSMSend(PRFileDesc *fd, const void *buf, int32_t amount,
     int flags, PRIntervalTime timeout)
 {
   nsNSSShutDownPreventionLock locker;
@@ -1134,19 +1133,19 @@ static int32_t PR_CALLBACK PSMSend(PRFileDesc *fd, const void *buf, int32_t amou
   return checkHandshake(bytesWritten, false, fd, socketInfo);
 }
 
-static int32_t PR_CALLBACK
+static int32_t
 nsSSLIOLayerRead(PRFileDesc* fd, void* buf, int32_t amount)
 {
   return PSMRecv(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
 }
 
-static int32_t PR_CALLBACK
+static int32_t
 nsSSLIOLayerWrite(PRFileDesc* fd, const void* buf, int32_t amount)
 {
   return PSMSend(fd, buf, amount, 0, PR_INTERVAL_NO_TIMEOUT);
 }
 
-static PRStatus PR_CALLBACK PSMConnectcontinue(PRFileDesc *fd, int16_t out_flags)
+static PRStatus PSMConnectcontinue(PRFileDesc *fd, int16_t out_flags)
 {
   nsNSSShutDownPreventionLock locker;
   if (!getSocketInfoIfRunning(fd, not_reading_or_writing, locker)) {
diff --git a/security/manager/ssl/src/nsNSSShutDown.cpp b/security/manager/ssl/src/nsNSSShutDown.cpp
index 95440e416db2..11512f1a5649 100644
--- a/security/manager/ssl/src/nsNSSShutDown.cpp
+++ b/security/manager/ssl/src/nsNSSShutDown.cpp
@@ -157,7 +157,7 @@ nsresult nsNSSShutDownList::doPK11Logout()
   return NS_OK;
 }
 
-PLDHashOperator PR_CALLBACK
+PLDHashOperator
 nsNSSShutDownList::doPK11LogoutHelper(PLDHashTable *table, 
   PLDHashEntryHdr *hdr, uint32_t number, void *arg)
 {
@@ -209,7 +209,7 @@ nsresult nsNSSShutDownList::evaporateAllNSSResources()
   return NS_OK;
 }
 
-PLDHashOperator PR_CALLBACK
+PLDHashOperator
 nsNSSShutDownList::evaporateAllNSSResourcesHelper(PLDHashTable *table, 
   PLDHashEntryHdr *hdr, uint32_t number, void *arg)
 {
diff --git a/security/manager/ssl/src/nsNSSShutDown.h b/security/manager/ssl/src/nsNSSShutDown.h
index f8aff504a99d..91829d130e4a 100644
--- a/security/manager/ssl/src/nsNSSShutDown.h
+++ b/security/manager/ssl/src/nsNSSShutDown.h
@@ -147,11 +147,11 @@ public:
   
 private:
   nsNSSShutDownList();
-  static PLDHashOperator PR_CALLBACK
+  static PLDHashOperator
   evaporateAllNSSResourcesHelper(PLDHashTable *table, PLDHashEntryHdr *hdr,
                                                         uint32_t number, void *arg);
 
-  static PLDHashOperator PR_CALLBACK
+  static PLDHashOperator
   doPK11LogoutHelper(PLDHashTable *table, PLDHashEntryHdr *hdr,
                                                     uint32_t number, void *arg);
 protected:
diff --git a/security/manager/ssl/src/nsPKCS12Blob.cpp b/security/manager/ssl/src/nsPKCS12Blob.cpp
index 01ddcc592b4e..9b853b4ebc58 100644
--- a/security/manager/ssl/src/nsPKCS12Blob.cpp
+++ b/security/manager/ssl/src/nsPKCS12Blob.cpp
@@ -587,7 +587,7 @@ nsPKCS12Blob::inputToDecoder(SEC_PKCS12DecoderContext *dcx, nsIFile *file)
 
 // digest_open
 // prepare a memory buffer for reading/writing digests
-SECStatus PR_CALLBACK
+SECStatus
 nsPKCS12Blob::digest_open(void *arg, PRBool reading)
 {
   nsPKCS12Blob *cx = reinterpret_cast<nsPKCS12Blob *>(arg);
@@ -622,7 +622,7 @@ nsPKCS12Blob::digest_open(void *arg, PRBool reading)
 // digest_close
 // destroy a possibly active iterator
 // remove the data buffer if requested
-SECStatus PR_CALLBACK
+SECStatus
 nsPKCS12Blob::digest_close(void *arg, PRBool remove_it)
 {
   nsPKCS12Blob *cx = reinterpret_cast<nsPKCS12Blob *>(arg);
@@ -641,7 +641,7 @@ nsPKCS12Blob::digest_close(void *arg, PRBool remove_it)
 
 // digest_read
 // read bytes from the memory buffer
-int PR_CALLBACK
+int
 nsPKCS12Blob::digest_read(void *arg, unsigned char *buf, unsigned long len)
 {
   nsPKCS12Blob *cx = reinterpret_cast<nsPKCS12Blob *>(arg);
@@ -664,7 +664,7 @@ nsPKCS12Blob::digest_read(void *arg, unsigned char *buf, unsigned long len)
 
 // digest_write
 // append bytes to the memory buffer
-int PR_CALLBACK
+int
 nsPKCS12Blob::digest_write(void *arg, unsigned char *buf, unsigned long len)
 {
   nsPKCS12Blob *cx = reinterpret_cast<nsPKCS12Blob *>(arg);
@@ -683,7 +683,7 @@ nsPKCS12Blob::digest_write(void *arg, unsigned char *buf, unsigned long len)
 // nickname_collision
 // what to do when the nickname collides with one already in the db.
 // TODO: not handled, throw a dialog allowing the nick to be changed?
-SECItem * PR_CALLBACK
+SECItem *
 nsPKCS12Blob::nickname_collision(SECItem *oldNick, PRBool *cancel, void *wincx)
 {
   nsNSSShutDownPreventionLock locker;
@@ -745,7 +745,7 @@ nsPKCS12Blob::nickname_collision(SECItem *oldNick, PRBool *cancel, void *wincx)
 
 // write_export_file
 // write bytes to the exported PKCS#12 file
-void PR_CALLBACK
+void
 nsPKCS12Blob::write_export_file(void *arg, const char *buf, unsigned long len)
 {
   nsPKCS12Blob *cx = (nsPKCS12Blob *)arg;
diff --git a/security/manager/ssl/src/nsPKCS12Blob.h b/security/manager/ssl/src/nsPKCS12Blob.h
index 17ebb3351207..f1e0cfda4c2b 100644
--- a/security/manager/ssl/src/nsPKCS12Blob.h
+++ b/security/manager/ssl/src/nsPKCS12Blob.h
@@ -87,12 +87,12 @@ private:
   bool        mTokenSet;
 
   // C-style callback functions for the NSS PKCS#12 library
-  static SECStatus PR_CALLBACK digest_open(void *, PRBool);
-  static SECStatus PR_CALLBACK digest_close(void *, PRBool);
-  static int       PR_CALLBACK digest_read(void *, unsigned char *, unsigned long);
-  static int       PR_CALLBACK digest_write(void *, unsigned char *, unsigned long);
-  static SECItem * PR_CALLBACK nickname_collision(SECItem *, PRBool *, void *);
-  static void PR_CALLBACK write_export_file(void *arg, const char *buf, unsigned long len);
+  static SECStatus digest_open(void *, PRBool);
+  static SECStatus digest_close(void *, PRBool);
+  static int       digest_read(void *, unsigned char *, unsigned long);
+  static int       digest_write(void *, unsigned char *, unsigned long);
+  static SECItem * nickname_collision(SECItem *, PRBool *, void *);
+  static void write_export_file(void *arg, const char *buf, unsigned long len);
 
 };
 
diff --git a/security/manager/ssl/src/nsPSMBackgroundThread.cpp b/security/manager/ssl/src/nsPSMBackgroundThread.cpp
index ddb6c322a993..9e9304168c86 100644
--- a/security/manager/ssl/src/nsPSMBackgroundThread.cpp
+++ b/security/manager/ssl/src/nsPSMBackgroundThread.cpp
@@ -7,7 +7,7 @@
 
 using namespace mozilla;
 
-void PR_CALLBACK nsPSMBackgroundThread::nsThreadRunner(void *arg)
+void nsPSMBackgroundThread::nsThreadRunner(void *arg)
 {
   nsPSMBackgroundThread *self = static_cast<nsPSMBackgroundThread *>(arg);
   PR_SetCurrentThreadName(self->mName.BeginReading());
diff --git a/security/manager/ssl/src/nsPSMBackgroundThread.h b/security/manager/ssl/src/nsPSMBackgroundThread.h
index 4a2c85e9feda..f9d8538cee2c 100644
--- a/security/manager/ssl/src/nsPSMBackgroundThread.h
+++ b/security/manager/ssl/src/nsPSMBackgroundThread.h
@@ -14,7 +14,7 @@
 class nsPSMBackgroundThread
 {
 protected:
-  static void PR_CALLBACK nsThreadRunner(void *arg);
+  static void nsThreadRunner(void *arg);
   virtual void Run(void) = 0;
 
   // used to join the thread
diff --git a/security/manager/ssl/src/nsProtectedAuthThread.cpp b/security/manager/ssl/src/nsProtectedAuthThread.cpp
index f0da499f2b4d..7dd0857310b3 100644
--- a/security/manager/ssl/src/nsProtectedAuthThread.cpp
+++ b/security/manager/ssl/src/nsProtectedAuthThread.cpp
@@ -16,7 +16,7 @@ using namespace mozilla::psm;
 
 NS_IMPL_THREADSAFE_ISUPPORTS1(nsProtectedAuthThread, nsIProtectedAuthThread)
 
-static void PR_CALLBACK nsProtectedAuthThreadRunner(void *arg)
+static void nsProtectedAuthThreadRunner(void *arg)
 {
     PR_SetCurrentThreadName("Protected Auth");
 
diff --git a/security/manager/ssl/src/nsSmartCardMonitor.cpp b/security/manager/ssl/src/nsSmartCardMonitor.cpp
index 8f2b87ee58fd..0284a4f9d6f1 100644
--- a/security/manager/ssl/src/nsSmartCardMonitor.cpp
+++ b/security/manager/ssl/src/nsSmartCardMonitor.cpp
@@ -98,7 +98,7 @@ SmartCardThreadList::Add(SmartCardMonitoringThread *thread)
 
 
 // We really should have a Unity PL Hash function...
-static PR_CALLBACK PLHashNumber
+static PLHashNumber
 unity(const void *key) { return PLHashNumber(NS_PTR_TO_INT32(key)); }
 
 SmartCardMonitoringThread::SmartCardMonitoringThread(SECMODModule *module_)
diff --git a/testing/mochitest/ssltunnel/ssltunnel.cpp b/testing/mochitest/ssltunnel/ssltunnel.cpp
index 4c2d52c2e1fd..527affa04937 100644
--- a/testing/mochitest/ssltunnel/ssltunnel.cpp
+++ b/testing/mochitest/ssltunnel/ssltunnel.cpp
@@ -265,7 +265,7 @@ bool shutdown_server = false;
 bool do_http_proxy = false;
 bool any_host_spec_config = false;
 
-PR_CALLBACK int ClientAuthValueComparator(const void *v1, const void *v2)
+int ClientAuthValueComparator(const void *v1, const void *v2)
 {
   int a = *static_cast<const client_auth_option*>(v1) -
           *static_cast<const client_auth_option*>(v2);
diff --git a/widget/gtk2/nsCUPSShim.h b/widget/gtk2/nsCUPSShim.h
index 6e756e2ffb89..ed43b0e7b1d6 100644
--- a/widget/gtk2/nsCUPSShim.h
+++ b/widget/gtk2/nsCUPSShim.h
@@ -28,24 +28,24 @@ typedef struct               /**** Destination ****/
     cups_option_t *options;    /* Options */
 } cups_dest_t;
 
-typedef cups_dest_t* (PR_CALLBACK *CupsGetDestType)(const char *printer,
-                                                    const char *instance,
-                                                    int num_dests, 
-                                                    cups_dest_t *dests);
-typedef int (PR_CALLBACK *CupsGetDestsType)(cups_dest_t **dests);
-typedef int (PR_CALLBACK *CupsFreeDestsType)(int         num_dests,
-                                             cups_dest_t *dests);
-typedef int (PR_CALLBACK *CupsPrintFileType)(const char    *printer,
-                                             const char    *filename,
-                                             const char    *title,
-                                             int           num_options,
-                                             cups_option_t *options);
-typedef int (PR_CALLBACK *CupsTempFdType)(char *filename,
-                                          int   length);
-typedef int (PR_CALLBACK *CupsAddOptionType)(const char    *name,
-                                             const char    *value,
-                                             int           num_options,
-                                             cups_option_t **options);
+typedef cups_dest_t* (*CupsGetDestType)(const char *printer,
+                                        const char *instance,
+                                        int num_dests,
+                                        cups_dest_t *dests);
+typedef int (*CupsGetDestsType)(cups_dest_t **dests);
+typedef int (*CupsFreeDestsType)(int         num_dests,
+                                 cups_dest_t *dests);
+typedef int (*CupsPrintFileType)(const char    *printer,
+                                 const char    *filename,
+                                 const char    *title,
+                                 int           num_options,
+                                 cups_option_t *options);
+typedef int (*CupsTempFdType)(char *filename,
+                              int   length);
+typedef int (*CupsAddOptionType)(const char    *name,
+                                 const char    *value,
+                                 int           num_options,
+                                 cups_option_t **options);
 
 struct PRLibrary;
 
diff --git a/xpcom/threads/nsProcess.h b/xpcom/threads/nsProcess.h
index 5f32239a761c..6d02dc59186e 100644
--- a/xpcom/threads/nsProcess.h
+++ b/xpcom/threads/nsProcess.h
@@ -44,7 +44,7 @@ public:
 
 private:
   ~nsProcess();
-  static void PR_CALLBACK Monitor(void *arg);
+  static void Monitor(void *arg);
   void ProcessComplete();
   nsresult CopyArgsAndRunProcess(bool blocking, const char** args,
                                  uint32_t count, nsIObserver* observer,
diff --git a/xpcom/threads/nsProcessCommon.cpp b/xpcom/threads/nsProcessCommon.cpp
index 6a37b4426b9e..028aff10627b 100644
--- a/xpcom/threads/nsProcessCommon.cpp
+++ b/xpcom/threads/nsProcessCommon.cpp
@@ -221,7 +221,7 @@ static int assembleCmdLine(char *const *argv, PRUnichar **wideCmdLine,
 }
 #endif
 
-void PR_CALLBACK nsProcess::Monitor(void *arg)
+void nsProcess::Monitor(void *arg)
 {
     nsRefPtr<nsProcess> process = dont_AddRef(static_cast<nsProcess*>(arg));