diff --git a/src/Makefile.in b/src/Makefile.in
index 4bf742008..e8bb467c3 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -84,7 +84,7 @@ maintainer-copy::
 clean mostlyclean distclean maintainer-clean::
 	-rm -rf obj_* *.log *.dmp *.vpd core
 	-rm -f *.o *.d perlxsi.c *_gen_*
-	-rm -f *__gen*
+	-rm -f *__gen* obj_*
 	-rm -f .objcache*
 
 distclean maintainer-clean::
diff --git a/test_regress/Makefile b/test_regress/Makefile
index 6f36732e7..f230222d8 100644
--- a/test_regress/Makefile
+++ b/test_regress/Makefile
@@ -88,3 +88,4 @@ print-cxx-version:
 maintainer-copy::
 clean mostlyclean distclean maintainer-clean::
 	-rm -rf obj_* simv* simx* csrc cov_work INCA_libs *.log *.key logs vc_hdrs.h
+	-rm -rf t/obj_*