--- Makefile	(Asterisk 13.38.3)
+++ Makefile	(working copy)
@@ -117 +117 @@
-_ASTCFLAGS:=$(CONFIG_CFLAGS) $(CONFIG_SIGNED_CHAR)
+_ASTCFLAGS:=$(CONFIG_SIGNED_CHAR)
--- Makefile.rules	(Asterisk 13.38.3)
+++ Makefile.rules	(working copy)
@@ -94,15 +94,12 @@
 
-ifeq ($(findstring $(CONFIG_CFLAGS),$(_ASTCFLAGS)),)
-    _ASTCFLAGS+=$(CONFIG_CFLAGS)
-endif
-
 # shortcuts for common combinations of flags; these must be recursively expanded so that
 # per-target settings will be applied
-CC_CFLAGS=$(PTHREAD_CFLAGS) $(_ASTCFLAGS) $(ASTCFLAGS)
-CXX_CFLAGS=$(PTHREAD_CFLAGS) $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations $(AST_DECLARATION_AFTER_STATEMENT),$(_ASTCFLAGS) $(ASTCFLAGS))
-
+CC_CFLAGS=$(PTHREAD_CFLAGS) $(_ASTCFLAGS)
 # Clang -Werror warning suppressions
 ifeq ($(C_COMPILER_FAMILY),clang)
-	CC_CFLAGS+=-Wno-unused-value -Wno-parentheses-equality
+	CC_CFLAGS+=-Wno-unused-value -Wparentheses-equality
 endif
+CC_CFLAGS+=$(CONFIG_CFLAGS) $(ASTCFLAGS)
+
+CXX_CFLAGS=$(PTHREAD_CFLAGS) $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations $(AST_DECLARATION_AFTER_STATEMENT),$(_ASTCFLAGS) $(ASTCFLAGS))