diff --git a/docs/Makefile b/docs/Makefile
index 94224689..9be55735 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -48,7 +48,7 @@ help:
 	@echo "  doctest	to run all doctests embedded in the documentation (if enabled)"
 
 clean:
-	rm $(AUTOSUMMARYDIR)/*
+	rm -f $(AUTOSUMMARYDIR)/*
 	rm -rf $(BUILDDIR)/*
 
 html: