diff --git a/extensions/auth/gssapi.h b/extensions/auth/gssapi.h
index 8954991d6d5..07804ecbc6c 100644
--- a/extensions/auth/gssapi.h
+++ b/extensions/auth/gssapi.h
@@ -94,6 +94,10 @@
 
 EXTERN_C_BEGIN
 
+#if defined(XP_MACOSX)
+#    pragma pack(push,2)
+#endif
+
 /*
  * If the platform supports the xom.h header file, it should be
  * included here.
@@ -834,6 +838,9 @@ GSS_CALLCONV GSS_FUNC(gss_duplicate_name)
               );
 
 
+#if defined(XP_MACOSX)
+#    pragma pack(pop)
+#endif
 
 EXTERN_C_END