diff --git a/src/string_bytes.cc b/src/string_bytes.cc
index e1f2d92bf2e30d..0e6b8b842141c5 100644
--- a/src/string_bytes.cc
+++ b/src/string_bytes.cc
@@ -684,11 +684,8 @@ MaybeLocal<Value> StringBytes::Encode(Isolate* isolate,
     }
 
     default:
-      CHECK(0 && "unknown encoding");
-      break;
+      UNREACHABLE("unknown encoding");
   }
-
-  UNREACHABLE();
 }