diff --git a/kong/runloop/wasm.lua b/kong/runloop/wasm.lua
index 6a7bcd9e9282..3ae3f7e8c029 100644
--- a/kong/runloop/wasm.lua
+++ b/kong/runloop/wasm.lua
@@ -134,7 +134,7 @@ do
 
     local s = buf:get()
 
-    buf:free()
+    buf:reset()
 
     return sha256(s)
   end