diff --git a/src/nfreplay/send_v9.c b/src/nfreplay/send_v9.c
index 33418fc3..2b4f6856 100644
--- a/src/nfreplay/send_v9.c
+++ b/src/nfreplay/send_v9.c
@@ -177,7 +177,7 @@ static outTemplate_t *GetOutputTemplate(recordHandle_t *recordHandle) {
 
     uint64_t elementBits = 0;
     for (int i = 0; i < MAXEXTENSIONS; i++) {
-        if (recordHandle->extensionList[i]) elementBits |= 1 << i;
+        if (recordHandle->extensionList[i]) elementBits |= (uint64_t)1 << i;
     }
 
     outTemplate_t **t = &outTemplates;