--- a/extensions/auth/nsAuthGSSAPI.cpp
+++ b/extensions/auth/nsAuthGSSAPI.cpp
@@ -113,19 +113,25 @@ gssInit()
 
     if (!libPath.IsEmpty()) {
         LOG(("Attempting to load user specified library [%s]\n", libPath.get()));
         gssNativeImp = false;
         lib = PR_LoadLibrary(libPath.get());
     }
     else {
 #ifdef XP_WIN
-        char *libName = PR_GetLibraryName(nullptr, "gssapi32");
+        #ifdef _WIN64
+        static const char *kLibName = "gssapi64";
+        #else
+        static const char *kLibName = "gssapi32";
+        #endif
+
+        char *libName = PR_GetLibraryName(nullptr, kLibName);
         if (libName) {
-            lib = PR_LoadLibrary("gssapi32");
+            lib = PR_LoadLibrary(kLibName);
             PR_FreeLibraryName(libName);
         }
 #elif defined(__OpenBSD__)
         /* OpenBSD doesn't register inter-library dependencies in basesystem
          * libs therefor we need to load all the libraries gssapi depends on,
          * in the correct order and with LD_GLOBAL for GSSAPI auth to work
          * fine.
          */