diff --git a/makefile.basic b/makefile.basic
index 20c770c..38c1b3d 100644
--- a/makefile.basic
+++ b/makefile.basic
@@ -140,7 +140,7 @@ endef
 .PHONY: cflags-update
 cflags-update:
 ifeq ($(SAVECFLAGS),1)
-ifneq ($(subst $(DEPDIR)/,$(DEPDIR)/cflags-update,$(ALL_COMPILEFLAGS)),$(OLD_COMPILEFLAGS))
+ifneq ($(subst -MF"$(DEPDIR)/",-MF"$(DEPDIR)/cflags-update",$(ALL_COMPILEFLAGS)),$(OLD_COMPILEFLAGS))
 	$(file >$(CFLAGS_TMPFILE),$(ALL_COMPILEFLAGS))
 endif
 endif
diff --git a/makefile.library b/makefile.library
index 6c0ef88..402cd59 100644
--- a/makefile.library
+++ b/makefile.library
@@ -151,7 +151,7 @@ endef
 .PHONY: cflags-update
 cflags-update:
 ifeq ($(SAVECFLAGS),1)
-ifneq ($(subst $(DEPDIR)/,$(DEPDIR)/cflags-update,$(ALL_COMPILEFLAGS)),$(OLD_COMPILEFLAGS))
+ifneq ($(subst -MF"$(DEPDIR)/",-MF"$(DEPDIR)/cflags-update",$(ALL_COMPILEFLAGS)),$(OLD_COMPILEFLAGS))
 	$(file >$(CFLAGS_TMPFILE),$(ALL_COMPILEFLAGS))
 endif
 endif