diff --git a/intl/uconv/Makefile.in b/intl/uconv/Makefile.in
index 3224c24c1ddb..064c94b2ac50 100644
--- a/intl/uconv/Makefile.in
+++ b/intl/uconv/Makefile.in
@@ -40,6 +40,10 @@ include $(DEPTH)/config/autoconf.mk
 
 DIRS		= idl public src ucvja ucvcn ucvlatin ucvtw ucvtw2 ucvko ucvibm
 
+ifdef MOZ_MATHML
+DIRS           += ucvmath
+endif
+
 #ifdef ENABLE_TESTS
 #DIRS		+= tests
 #endif