diff --git a/cffu-core/src/main/java/io/foldright/cffu/CffuFactory.java b/cffu-core/src/main/java/io/foldright/cffu/CffuFactory.java
index 01af59e4..31acaf03 100644
--- a/cffu-core/src/main/java/io/foldright/cffu/CffuFactory.java
+++ b/cffu-core/src/main/java/io/foldright/cffu/CffuFactory.java
@@ -275,7 +275,7 @@ public <T> Cffu<T> newIncompleteCffu() {
     public <T> Cffu<T> toCffu(CompletionStage<T> stage) {
         requireNonNull(stage, "stage is null");
 
-        if ("java.util.concurrent.CompletableFuture$MinimalStage".equals(stage.getClass().getName())) {
+        if (CompletableFutureUtils.isMinimalStageCf(stage)) {
             return newMin((CompletableFuture<T>) stage);
         } else if (stage instanceof CompletableFuture) {
             return new0((CompletableFuture<T>) stage);
@@ -433,10 +433,10 @@ public final <T> Cffu<List<T>> allResultsOfFastFail(CompletionStage<? extends T>
      * If the given stage is successful, its result is the completed value; Otherwise the given valueIfNotSuccess.
      * (aka the result extraction logic is {@link Cffu#getSuccessNow(Object)}).
      *
-     * @param timeout       how long to wait in units of {@code unit}
-     * @param unit          a {@code TimeUnit} determining how to interpret the {@code timeout} parameter
+     * @param timeout           how long to wait in units of {@code unit}
+     * @param unit              a {@code TimeUnit} determining how to interpret the {@code timeout} parameter
      * @param valueIfNotSuccess the value to return if not completed successfully
-     * @param cfs           the stages
+     * @param cfs               the stages
      * @see Cffu#getSuccessNow(Object)
      */
     // TODO * @see CompletableFutureUtils#MGetSuccessNow(Object, CompletionStage[])
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 fea4462a..66885aaa 100644
--- a/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
+++ b/cffu-core/src/main/java/io/foldright/cffu/CompletableFutureUtils.java
@@ -208,7 +208,7 @@ public static <T> CompletableFuture<List<T>> mostResultsOfSuccess(
 
         if (cfs.length == 0) return CompletableFuture.completedFuture(arrayList());
         if (cfs.length == 1) {
-            final CompletableFuture<T> f = copy(toNonMinCf(cfs[0]));
+            final CompletableFuture<T> f = toCfCopy(cfs[0]);
             return orTimeout(f, timeout, unit).handle((unused, ex) -> arrayList(getSuccessNow(f, valueIfNotSuccess)));
         }
 
@@ -310,11 +310,11 @@ private static <T> CompletableFuture<T>[] toCfArray0(
      * so the returned CF instances MUST NOT be written(e.g. {@link CompletableFuture#complete(Object)}).
      * Otherwise, the caller should defensive copy instead of writing it directly.
      */
-    @SuppressWarnings({"unchecked", "rawtypes"})
+    @SuppressWarnings("unchecked")
     private static <T> CompletableFuture<T> toCf(CompletionStage<? extends T> s) {
         if (s instanceof CompletableFuture) return (CompletableFuture<T>) s;
-        else if (s instanceof Cffu) return ((Cffu) s).cffuUnwrap();
-        else return (CompletableFuture) s.toCompletableFuture();
+        else if (s instanceof Cffu) return ((Cffu<T>) s).cffuUnwrap();
+        else return (CompletableFuture<T>) s.toCompletableFuture();
     }
 
     /**
@@ -324,15 +324,26 @@ private static <T> CompletableFuture<T> toCf(CompletionStage<? extends T> s) {
      * so the returned CF instances MUST NOT be written(e.g. {@link CompletableFuture#complete(Object)}).
      * Otherwise, the caller should defensive copy instead of writing it directly.
      */
-    @SuppressWarnings({"unchecked", "rawtypes"})
+    @SuppressWarnings("unchecked")
     private static <T> CompletableFuture<T> toNonMinCf(CompletionStage<? extends T> s) {
         final CompletableFuture<T> f;
         if (s instanceof CompletableFuture) f = (CompletableFuture<T>) s;
-        else if (s instanceof Cffu) f = ((Cffu) s).cffuUnwrap();
-        else return (CompletableFuture) s.toCompletableFuture();
+        else if (s instanceof Cffu) f = ((Cffu<T>) s).cffuUnwrap();
+        else return (CompletableFuture<T>) s.toCompletableFuture();
+
+        return isMinimalStageCf(f) ? f.toCompletableFuture() : f;
+    }
+
+    /**
+     * Converts CompletionStage to CompletableFuture copy.
+     */
+    private static <T> CompletableFuture<T> toCfCopy(CompletionStage<? extends T> s) {
+        final CompletableFuture<T> f = toCf(s);
+        return isMinimalStageCf(f) ? f.toCompletableFuture() : copy(f);
+    }
 
-        return "java.util.concurrent.CompletableFuture$MinimalStage".equals(s.getClass().getName())
-                ? f.toCompletableFuture() : f;
+    static <T> boolean isMinimalStageCf(CompletionStage<? extends T> s) {
+        return "java.util.concurrent.CompletableFuture$MinimalStage".equals(s.getClass().getName());
     }
 
     ////////////////////////////////////////////////////////////////////////////////
@@ -385,7 +396,7 @@ public static <T> CompletableFuture<T> anyOfSuccess(CompletionStage<? extends T>
         requireCfsAndEleNonNull(cfs);
         final int size = cfs.length;
         if (size == 0) return failedFuture(new NoCfsProvidedException());
-        if (size == 1) return copy(toCf(cfs[0]));
+        if (size == 1) return toCfCopy(cfs[0]);
 
         // NOTE: fill ONE MORE element of successOrBeIncompleteCfs LATER
         final CompletableFuture<?>[] successOrBeIncomplete = new CompletableFuture[size + 1];
diff --git a/cffu-kotlin/src/main/java/io/foldright/cffu/kotlin/CffuExtensions.kt b/cffu-kotlin/src/main/java/io/foldright/cffu/kotlin/CffuExtensions.kt
index c2e11073..12aa52fb 100644
--- a/cffu-kotlin/src/main/java/io/foldright/cffu/kotlin/CffuExtensions.kt
+++ b/cffu-kotlin/src/main/java/io/foldright/cffu/kotlin/CffuExtensions.kt
@@ -2,7 +2,6 @@ package io.foldright.cffu.kotlin
 
 import io.foldright.cffu.Cffu
 import io.foldright.cffu.CffuFactory
-import io.foldright.cffu.CompletableFutureUtils
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.CompletionStage
 import java.util.concurrent.TimeUnit