diff --git a/lib/rb/Makefile.am b/lib/rb/Makefile.am
index 137edb4..1841065 100755
--- a/lib/rb/Makefile.am
+++ b/lib/rb/Makefile.am
@@ -31,6 +31,7 @@
 clean-local:
 	$(BUNDLER) install
 	$(BUNDLER) exec rake clean
+	$(RM) -r spec/gen-rb/
 
 check-local: all
 	$(BUNDLER) install
@@ -38,6 +39,9 @@
 
 endif
 
+dist-hook:
+	$(RM) -r $(distdir)/spec/gen-rb/
+
 EXTRA_DIST = \
 	coding_standards.md \
 	Rakefile \