diff --git a/src/hb-string-array.hh b/src/hb-string-array.hh
index 9d77ec478..e7ac11923 100644
--- a/src/hb-string-array.hh
+++ b/src/hb-string-array.hh
@@ -80,5 +80,6 @@ HB_STRING_ARRAY_NAME (unsigned int i)
 #undef HB_STRING_ARRAY_TYPE_NAME
 #undef HB_STRING_ARRAY_POOL_NAME
 #undef HB_STRING_ARRAY_OFFS_NAME
+#undef HB_STRING_ARRAY_LENG_NAME
 
 #endif /* HB_STRING_ARRAY_HH */