diff --git a/Tools/Makefile.preamble b/Tools/Makefile.preamble
index 22bfdc3d4..3a0671a1c 100644
--- a/Tools/Makefile.preamble
+++ b/Tools/Makefile.preamble
@@ -39,7 +39,7 @@
 ADDITIONAL_CPPFLAGS += -DHAVE_LIBXML=$(HAVE_LIBXML)
 
 # Additional flags to pass to the Objective-C compiler
-#ADDITIONAL_OBJCFLAGS += 
+ADDITIONAL_OBJCFLAGS += -Wall
 
 # Additional flags to pass to the C compiler
 #ADDITIONAL_CFLAGS +=