diff --git a/microscoped-core/src/main/java/org/tomitribe/microscoped/core/Scope.java b/microscoped-core/src/main/java/org/tomitribe/microscoped/core/Scope.java
index eebca4c..a18b023 100644
--- a/microscoped-core/src/main/java/org/tomitribe/microscoped/core/Scope.java
+++ b/microscoped-core/src/main/java/org/tomitribe/microscoped/core/Scope.java
@@ -43,7 +43,11 @@ public Key getKey() {
      * @return existing or newly created bean instance, never null
      */
     public <T> T get(final Contextual<T> contextual, final CreationalContext<T> creationalContext) {
-        return (T) instances.computeIfAbsent(contextual, c -> new Instance<>(contextual, creationalContext)).get();
+        if (!instances.containsKey(contextual)) {
+            final Instance<T> instance = new Instance<>(contextual, creationalContext);
+            instances.putIfAbsent(contextual, instance);
+        }
+        return (T) instances.get(contextual).get();
     }
 
     /**