--- a/configure.in
+++ b/configure.in
@@ -6906,16 +6906,17 @@ dnl ====================================
 MOZ_ARG_DISABLE_BOOL(logging,
 [  --disable-logging       Disable logging facilities],
     NS_DISABLE_LOGGING=1,
     NS_DISABLE_LOGGING= )
 if test "$NS_DISABLE_LOGGING"; then
     AC_DEFINE(NS_DISABLE_LOGGING)
 else
     AC_DEFINE(MOZ_LOGGING)
+    AC_DEFINE(FORCE_PR_LOG)
 fi
 
 dnl ========================================================
 dnl = This will enable logging of addref, release, ctor, dtor.
 dnl ========================================================
 _ENABLE_LOGREFCNT=42
 MOZ_ARG_ENABLE_BOOL(logrefcnt,
 [  --enable-logrefcnt      Enable logging of refcounts (default=debug) ],