diff --git a/src/glut/glx/Makefile b/src/glut/glx/Makefile
index 6889cd4b402..69f8052c092 100644
--- a/src/glut/glx/Makefile
+++ b/src/glut/glx/Makefile
@@ -137,4 +137,4 @@ depend: $(SOURCES)
 	@ $(MKDEP) $(MKDEP_OPTIONS) -I$(TOP)/include $(SOURCES) \
 		$(X11_INCLUDES) > /dev/null 
 
-include depend
+-include depend
diff --git a/src/glw/Makefile b/src/glw/Makefile
index 39352f05320..776b1aa5bfb 100644
--- a/src/glw/Makefile
+++ b/src/glw/Makefile
@@ -71,4 +71,4 @@ depend: $(GLW_SOURCES)
 		$(X11_INCLUDES) > /dev/null
 
 
-include depend
+-include depend