diff --git a/rules.mak b/rules.mak
index 197a9d7abf..b21383beba 100644
--- a/rules.mak
+++ b/rules.mak
@@ -15,7 +15,7 @@ MAKEFLAGS += -rR
 QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
 
 # Same as -I$(SRC_PATH) -I., but for the nested source/object directories
-QEMU_CFLAGS += -I$(<D) -I$(@D)
+QEMU_INCLUDES += -I$(<D) -I$(@D)
 
 %.o: %.c
 	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  CC    $(TARGET_DIR)$@")