diff --git a/mozilla/configure.in b/mozilla/configure.in
index 03f5cdc03de..0fbf7a7ed3d 100644
--- a/mozilla/configure.in
+++ b/mozilla/configure.in
@@ -3437,9 +3437,16 @@ dnl = Timeline is off by default.
 dnl ========================================================
 MOZ_TIMELINE=
 MOZ_ARG_ENABLE_BOOL(timeline,
-[  --enable-timeline       Enable timeline services ],
+[  --enable-timeline       Enable timeline services (default=debug)],
+    _MOZ_TIMELINE=1 , ,
+    [ if test "$MOZ_DEBUG"; then
+        _MOZ_TIMELINE=1 
+    fi])
+
+if test "$_MOZ_TIMELINE"; then
     AC_DEFINE(MOZ_TIMELINE)
-    MOZ_TIMELINE=1)
+    MOZ_TIMELINE=1
+fi
 
 dnl ========================================================
 dnl Turn on reflow counting
@@ -3464,9 +3471,14 @@ dnl = Enable trace malloc
 dnl ========================================================
 NS_TRACE_MALLOC=
 MOZ_ARG_ENABLE_BOOL(trace-malloc,
-[  --enable-trace-malloc   Enable malloc tracing],
-    NS_TRACE_MALLOC=1 )
-if test "$NS_TRACE_MALLOC"; then
+[  --enable-trace-malloc   Enable malloc tracing (default=debug)],
+    _NS_TRACE_MALLOC=1 , ,
+    [ if test "$MOZ_DEBUG"; then
+        _NS_TRACE_MALLOC=1 
+    fi])
+
+if test "$_NS_TRACE_MALLOC"; then
+  NS_TRACE_MALLOC=1
   # Please, Mr. Linker Man, don't take away our symbol names
   MOZ_COMPONENTS_VERSION_SCRIPT_LDFLAGS=
   USE_ELF_DYNSTR_GC=