diff --git a/Makefile b/Makefile
index d86eaf0..9f0b679 100644
--- a/Makefile
+++ b/Makefile
@@ -273,17 +273,18 @@
 # Add paths to files in X-y to X-srcs
 # Add subdirs-y to subdirs
 includemakefiles= \
-	$(foreach class,classes subdirs $(classes) $(special-classes), $(eval $(class)-y:=)) \
-	$(eval -include $(1)) \
-	$(foreach class,$(classes-y), $(call add-class,$(class))) \
-	$(foreach special,$(special-classes), \
-		$(foreach item,$($(special)-y), $(call $(special)-handler,$(dir $(1)),$(item)))) \
-	$(foreach class,$(classes), \
-		$(eval $(class)-srcs+= \
-			$$(subst $(absobj)/,$(obj)/, \
-			$$(subst $(top)/,, \
-			$$(abspath $$(subst $(dir $(1))/,/,$$(addprefix $(dir $(1)),$$($(class)-y)))))))) \
-	$(eval subdirs+=$$(subst $(CURDIR)/,,$$(wildcard $$(abspath $$(addprefix $(dir $(1)),$$(subdirs-y))))))
+	$(if $(wildcard $(1)), \
+		$(foreach class,classes subdirs $(classes) $(special-classes), $(eval $(class)-y:=)) \
+		$(eval -include $(1)) \
+		$(foreach class,$(classes-y), $(call add-class,$(class))) \
+		$(foreach special,$(special-classes), \
+			$(foreach item,$($(special)-y), $(call $(special)-handler,$(dir $(1)),$(item)))) \
+		$(foreach class,$(classes), \
+			$(eval $(class)-srcs+= \
+				$$(subst $(absobj)/,$(obj)/, \
+				$$(subst $(top)/,, \
+				$$(abspath $$(subst $(dir $(1))/,/,$$(addprefix $(dir $(1)),$$($(class)-y)))))))) \
+		$(eval subdirs+=$$(subst $(CURDIR)/,,$$(wildcard $$(abspath $$(addprefix $(dir $(1)),$$(subdirs-y)))))))
 
 # For each path in $(subdirs) call includemakefiles
 # Repeat until subdirs is empty