diff --git a/xpcom/io/nsFastLoadFile.cpp b/xpcom/io/nsFastLoadFile.cpp
index aa0d03e2f5b6..1ce49142d3c7 100644
--- a/xpcom/io/nsFastLoadFile.cpp
+++ b/xpcom/io/nsFastLoadFile.cpp
@@ -230,6 +230,9 @@ static const char magic[] = MFL_FILE_MAGIC;
 
 // -------------------------- nsFastLoadFileReader --------------------------
 
+nsID nsFastLoadFileReader::nsFastLoadFooter::gDummyID;
+nsFastLoadFileReader::nsObjectMapEntry nsFastLoadFileReader::nsFastLoadFooter::gDummySharpObjectEntry; 
+
 NS_IMPL_ISUPPORTS_INHERITED3(nsFastLoadFileReader,
                              nsBinaryInputStream,
                              nsIObjectInputStream,
diff --git a/xpcom/io/nsFastLoadFile.h b/xpcom/io/nsFastLoadFile.h
index ad001f0a6cba..a9f8a03eb23a 100644
--- a/xpcom/io/nsFastLoadFile.h
+++ b/xpcom/io/nsFastLoadFile.h
@@ -299,22 +299,27 @@ class NS_COM nsFastLoadFileReader
                 PL_DHashTableFinish(&mURIMap);
         }
 
+        // These can't be static within GetID and GetSharpObjectEntry or the
+        // toolchains on HP-UX 10.20's, RH 7.0, and Mac OS X all barf at link
+        // time ("common symbols not allowed with MY_DHLIB output format", to
+        // quote the OS X rev of gcc).
+        static nsID gDummyID;
+        static nsObjectMapEntry gDummySharpObjectEntry;
+
         const nsID& GetID(NSFastLoadID aFastId) const {
-            static nsID dummy;
             PRUint32 index = aFastId - 1;
             NS_ASSERTION(index < mNumIDs, "aFastId out of range");
             if (index >= mNumIDs)
-                return dummy;
+                return gDummyID;
             return mIDMap[index];
         }
 
         nsObjectMapEntry&
         GetSharpObjectEntry(NSFastLoadOID aOID) const {
-            static nsObjectMapEntry dummy;
             PRUint32 index = MFL_OID_TO_SHARP_INDEX(aOID);
             NS_ASSERTION(index < mNumSharpObjects, "aOID out of range");
             if (index >= mNumSharpObjects)
-                return dummy;
+                return gDummySharpObjectEntry;
             return mObjectMap[index];
         }