diff --git a/doc/Makefile b/doc/Makefile
index 4da1e8a0..efc61de2 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -30,6 +30,7 @@ help:
 
 clean:
 	-rm -rf $(DEST)/*
+	-rm -rf source/api
 
 api:
 	mkdir -p source/api