--- a/mail/app/Makefile.in
+++ b/mail/app/Makefile.in
@@ -133,6 +133,7 @@ LIBS += \
 	$(APP_XPCOM_LIBS) \
 	$(NSPR_LIBS) \
 	$(TK_LIBS) \
+	$(MOZ_HUNSPELL_LIBS) \
 	$(NULL)
 
 # Add explicit X11 dependency when building against X11 toolkits