diff --git a/Cantera/cxx/src/.cvsignore b/Cantera/cxx/src/.cvsignore
index 57751bad9..db1a5c99a 100644
--- a/Cantera/cxx/src/.cvsignore
+++ b/Cantera/cxx/src/.cvsignore
@@ -1,2 +1,3 @@
 Makefile
 .depends
+SunWS_cache
diff --git a/Cantera/cxx/src/Makefile.in b/Cantera/cxx/src/Makefile.in
index f182790b1..33f0cfd52 100644
--- a/Cantera/cxx/src/Makefile.in
+++ b/Cantera/cxx/src/Makefile.in
@@ -40,6 +40,9 @@ $(CXXLIB): $(OBJS)
 
 clean:
 	$(RM) $(OBJS) $(CXXLIB)
+	(if test -d SunWS_cache ; then \
+           $(RM) -rf SunWS_cache ; \
+         fi )
 
 install:
 	@INSTALL@ $(CXXLIB) @prefix@/lib/cantera