diff --git a/profile/src/nsProfileAccess.cpp b/profile/src/nsProfileAccess.cpp
index 97c1d3c41c7e..44b24a6159b4 100644
--- a/profile/src/nsProfileAccess.cpp
+++ b/profile/src/nsProfileAccess.cpp
@@ -1625,7 +1625,11 @@ static struct sigaction SIGABRT_oldact;
 static struct sigaction SIGSEGV_oldact;
 static struct sigaction SIGTERM_oldact;
 
-void nsProfileLock::FatalSignalHandler(int signo)
+// There is no standard type definition for the type of sa_sigaction.
+typedef void (*my_sigaction_t)(int, siginfo_t*, void*);
+
+void nsProfileLock::FatalSignalHandler(int signo, siginfo_t* info,
+                                       void* context)
 {
     // Remove any locks still held.
     RemovePidLockFiles();
@@ -1660,12 +1664,22 @@ void nsProfileLock::FatalSignalHandler(int signo)
         break;
     }
 
-    if (oldact &&
-        oldact->sa_handler &&
-        oldact->sa_handler != SIG_DFL &&
-        oldact->sa_handler != SIG_IGN)
-    {
-        oldact->sa_handler(signo);
+    if (oldact) {
+        if (oldact->sa_flags & SA_SIGINFO) {
+            if (oldact->sa_sigaction &&
+                oldact->sa_sigaction != (my_sigaction_t) SIG_DFL &&
+                oldact->sa_sigaction != (my_sigaction_t) SIG_IGN)
+            {
+                oldact->sa_sigaction(signo, info, context);
+            }
+        } else {
+            if (oldact->sa_handler &&
+                oldact->sa_handler != SIG_DFL &&
+                oldact->sa_handler != SIG_IGN)
+            {
+                oldact->sa_handler(signo);
+            }
+        }
     }
 
     // Backstop exit call, just in case.
@@ -1929,14 +1943,16 @@ nsresult nsProfileLock::Lock(nsILocalFile* aFile)
                 // Don't arm a handler if the signal is being ignored, e.g.,
                 // because mozilla is run via nohup.
                 struct sigaction act, oldact;
-                act.sa_handler = FatalSignalHandler;
-                act.sa_flags = 0;
+                act.sa_sigaction = FatalSignalHandler;
+                act.sa_flags = SA_SIGINFO;
                 sigfillset(&act.sa_mask);
 
 #define CATCH_SIGNAL(signame)                                                 \
     PR_BEGIN_MACRO                                                            \
         if (sigaction(signame, NULL, &oldact) == 0 &&                         \
-            oldact.sa_handler != SIG_IGN)                                     \
+            ((oldact.sa_flags & SA_SIGINFO) ?                                 \
+               (oldact.sa_sigaction != (my_sigaction_t) SIG_IGN) :            \
+               (oldact.sa_handler != SIG_IGN)))                               \
         {                                                                     \
             sigaction(signame, &act, &signame##_oldact);                      \
         }                                                                     \
diff --git a/profile/src/nsProfileAccess.h b/profile/src/nsProfileAccess.h
index a96e29f488bf..98f98c2da670 100644
--- a/profile/src/nsProfileAccess.h
+++ b/profile/src/nsProfileAccess.h
@@ -33,6 +33,10 @@
 #include <windows.h>
 #endif
 
+#ifdef XP_UNIX
+#include <signal.h>
+#endif
+
 class ProfileStruct
 {    
 public:
@@ -198,7 +202,8 @@ private:
     LHANDLE                 mLockFileHandle;
 #elif defined (XP_UNIX)
     static void             RemovePidLockFiles();
-    static void             FatalSignalHandler(int signo);
+    static void             FatalSignalHandler(int signo, siginfo_t* info,
+                                               void* context);
     static PRCList          mPidLockList;
     char*                   mPidLockFileName;
     int                     mLockFileDesc;