diff --git a/cffu-core/src/main/java/io/foldright/cffu/CffuFactoryBuilder.java b/cffu-core/src/main/java/io/foldright/cffu/CffuFactoryBuilder.java
index 5c68449f..88a726ad 100644
--- a/cffu-core/src/main/java/io/foldright/cffu/CffuFactoryBuilder.java
+++ b/cffu-core/src/main/java/io/foldright/cffu/CffuFactoryBuilder.java
@@ -87,11 +87,12 @@ static CffuFactory resetDefaultExecutor(CffuFactory fac, Executor defaultExecuto
         return new CffuFactory(makeExecutor(defaultExecutor), fac.forbidObtrudeMethods());
     }
 
-    private static Executor makeExecutor(Executor executor) {
+    private static Executor makeExecutor(Executor defaultExecutor) {
         // check CffuMadeExecutor interface to avoid re-wrapping.
-        if (executor instanceof CffuMadeExecutor) return executor;
+        if (defaultExecutor instanceof CffuMadeExecutor) return defaultExecutor;
 
-        Executor wrapByProviders = wrapExecutorByProviders(CompletableFutureUtils.screenExecutor(executor));
+        requireNonNull(defaultExecutor, "defaultExecutor is null");
+        Executor wrapByProviders = wrapExecutorByProviders(CompletableFutureUtils.screenExecutor(defaultExecutor));
         return wrapMadeInterface(wrapByProviders);
     }
 
diff --git a/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java b/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
index ad0750fa..535fcfd9 100644
--- a/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
+++ b/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
@@ -3198,7 +3198,7 @@ public static <C extends CompletableFuture<?>> C cffuOrTimeout(C cfThis, long ti
     public static <C extends CompletableFuture<?>> C cffuOrTimeout(
             C cfThis, Executor executorWhenTimeout, long timeout, TimeUnit unit) {
         requireNonNull(cfThis, "cfThis is null");
-        requireNonNull(executorWhenTimeout, "executorWhenTimeout is null");
+        executorWhenTimeout = screenExecutor(requireNonNull(executorWhenTimeout, "executorWhenTimeout is null"));
         requireNonNull(unit, "unit is null");
 
         return hopExecutorIfAtCfDelayerThread(orTimeout(cfThis, timeout, unit), executorWhenTimeout);
@@ -3294,7 +3294,7 @@ C cffuCompleteOnTimeout(C cfThis, @Nullable T value, long timeout, TimeUnit unit
     public static <T, C extends CompletableFuture<? super T>>
     C cffuCompleteOnTimeout(C cfThis, @Nullable T value, Executor executorWhenTimeout, long timeout, TimeUnit unit) {
         requireNonNull(cfThis, "cfThis is null");
-        requireNonNull(executorWhenTimeout, "executorWhenTimeout is null");
+        executorWhenTimeout = screenExecutor(requireNonNull(executorWhenTimeout, "executorWhenTimeout is null"));
         requireNonNull(unit, "unit is null");
 
         return hopExecutorIfAtCfDelayerThread(completeOnTimeout(cfThis, value, timeout, unit), executorWhenTimeout);