--- MCONFIG.in
+++ MCONFIG.in
@@ -52,9 +52,10 @@
 
 CC = @CC@
 BUILD_CC = @BUILD_CC@
+DEFS = @DEFS@
 CFLAGS = @CFLAGS@
 CPPFLAGS = @INCLUDES@
-ALL_CFLAGS = $(CPPFLAGS) $(CFLAGS)
+ALL_CFLAGS = $(CPPFLAGS) $(DEFS) $(CFLAGS)
 LDFLAGS = @LDFLAGS@
 ALL_LDFLAGS = $(LDFLAGS) @LDFLAG_DYNAMIC@
 LDFLAGS_STATIC = $(LDFLAGS) @LDFLAG_STATIC@