diff --git a/src/hb-ot-layout-common-private.hh b/src/hb-ot-layout-common-private.hh
index 8ef8424de..1e75930cd 100644
--- a/src/hb-ot-layout-common-private.hh
+++ b/src/hb-ot-layout-common-private.hh
@@ -39,7 +39,7 @@ namespace OT {
 
 #define NOT_COVERED		((unsigned int) -1)
 #define MAX_NESTING_LEVEL	8
-#define MAX_CONTEXT_LENGTH	32
+#define MAX_CONTEXT_LENGTH	64