diff --git a/Makefile.am b/Makefile.am
index 6ca69fc7..75d502f1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2,6 +2,7 @@ ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
 
 # create default-config.h
 BUILT_SOURCES = default-config.h default-theme.h irssi-version.h
+CLEANFILES = default-config.h default-theme.h
 
 @MAINTAINER_MODE_TRUE@.PHONY: irssi-version.h