diff --git a/flow/src/main/java/flow/KeyManager.java b/flow/src/main/java/flow/KeyManager.java
index 51ecac3..af6bfdf 100644
--- a/flow/src/main/java/flow/KeyManager.java
+++ b/flow/src/main/java/flow/KeyManager.java
@@ -128,6 +128,9 @@ void tearDown(Object key) {
 
   private boolean decrementAndMaybeRemoveKey(Object key) {
     ManagedServices node = managedServices.get(key);
+    if(node == null) {
+      return false;
+    }
     node.uses--;
     if (key != ROOT_KEY && node.uses == 0) {
       int count = servicesFactories.size();