diff --git a/mozilla/rdf/Makefile.in b/mozilla/rdf/Makefile.in
index 862434eea49..ba277f8c9d1 100644
--- a/mozilla/rdf/Makefile.in
+++ b/mozilla/rdf/Makefile.in
@@ -24,6 +24,10 @@ include $(DEPTH)/config/autoconf.mk
 
 DIRS = base content datasource build
 
+ifdef ENABLE_TESTS
+DIRS += tests
+endif
+
 include $(topsrcdir)/config/config.mk
 
 include $(topsrcdir)/config/rules.mk