diff --git a/tools/debugger/gdbsx/Makefile b/tools/debugger/gdbsx/Makefile
index 8d7cd94a31..5571450a89 100644
--- a/tools/debugger/gdbsx/Makefile
+++ b/tools/debugger/gdbsx/Makefile
@@ -14,7 +14,7 @@ clean:
 
 .PHONY: distclean
 distclean: clean
-	set -e; for d in xg gx; do $(MAKE) -c $$d distclean; done
+	set -e; for d in xg gx; do $(MAKE) -C $$d distclean; done
 
 .PHONY: install
 install: all