diff --git a/test_problems/diamondSurf/.cvsignore b/test_problems/diamondSurf/.cvsignore
index d23c0e8e1..a3f944249 100644
--- a/test_problems/diamondSurf/.cvsignore
+++ b/test_problems/diamondSurf/.cvsignore
@@ -14,3 +14,4 @@ diamondSurf.pdb
 diamonda.xml
 outputa.txt
 test.xml
+SunWS_cache
diff --git a/test_problems/diamondSurf/Makefile.in b/test_problems/diamondSurf/Makefile.in
index 776c48c21..5198278f0 100644
--- a/test_problems/diamondSurf/Makefile.in
+++ b/test_problems/diamondSurf/Makefile.in
@@ -107,4 +107,7 @@ endif
 clean:
 	$(RM) $(OBJS) $(PROGRAM) $(DEPENDS) .depends
 	../../bin/rm_cvsignore
+	(if test -d SunWS_cache ; then \
+           $(RM) -rf SunWS_cache ; \
+         fi )