diff --git a/src/glut/glx/Makefile b/src/glut/glx/Makefile
index 9f995667b40..46185cebbc0 100644
--- a/src/glut/glx/Makefile
+++ b/src/glut/glx/Makefile
@@ -126,6 +126,6 @@ depend: $(SOURCES)
 	@ echo "running $(MKDEP)"
 	@ touch depend
 	@ $(MKDEP) $(MKDEP_OPTIONS) -I$(TOP)/include $(SOURCES) \
-		> /dev/null 
+		$(X11_INCLUDES) > /dev/null 
 
 include depend
diff --git a/src/glw/Makefile b/src/glw/Makefile
index 727c5838be5..ce6a30e9de3 100644
--- a/src/glw/Makefile
+++ b/src/glw/Makefile
@@ -61,7 +61,7 @@ $(TOP)/$(LIB_DIR)/$(GLW_LIB_NAME): $(OBJECTS)
 depend: $(GLW_SOURCES)
 	touch depend
 	$(MKDEP) $(MKDEP_OPTIONS) -I$(TOP)/include $(GLW_SOURCES) \
-		> /dev/null 
+		$(X11_INCLUDES) > /dev/null
 
 
 include depend