Makefile in ParseTree-1.3.2 vs Makefile in ParseTree-1.3.3

@@ -27,12 +27,10 @@
 audit:
 	ZenTest composite_sexp_processor.rb sexp_processor.rb test_all.rb test_composite_sexp_processor.rb test_sexp_processor.rb
 
 clean:
 	-find . -name \*~ | xargs rm
-	-rm -f diff diff.txt
-	-rm -r $$HOME/.ruby_inline
-	-rm -r doc
+	-rm -fr diff diff.txt *.gem doc $$HOME/.ruby_inline
 
 demo:
 	echo 1+1 | $(RUBY) $(RUBY_FLAGS) ./bin/parse_tree_show -f
 
 gem: