diff --git a/src/Makefile.sources b/src/Makefile.sources
index cbbad90d2..17362ba70 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -57,6 +57,7 @@ HB_BASE_sources = \
 	hb-ot-cff-common.hh \
 	hb-ot-cff1-table.cc \
 	hb-ot-cff1-table.hh \
+	hb-ot-cff1-std-str.hh \
 	hb-ot-cff2-table.cc \
 	hb-ot-cff2-table.hh \
 	hb-ot-cmap-table.hh \