diff --git a/GNUmakefile b/GNUmakefile
index 25dedc7..2a3172c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -1,3 +1,12 @@
+
+ifeq ($(GNUSTEP_MAKEFILES),)
+ GNUSTEP_MAKEFILES := $(shell gnustep-config --variable=GNUSTEP_MAKEFILES 2>/dev/null)
+endif
+ 
+ifeq ($(GNUSTEP_MAKEFILES),)
+ $(error You need to set GNUSTEP_MAKEFILES before compiling!)
+endif
+
 include $(GNUSTEP_MAKEFILES)/common.make
 
 -include config.make