diff --git a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistry.java b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistry.java
index 3f91ec3a4..d0ba385fd 100644
--- a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistry.java
+++ b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistry.java
@@ -195,8 +195,10 @@ public class BeanFactoryAwareFunctionRegistry
 				definition = functionNames[0];
 			}
 			else {
-				Assert.isTrue(this.registrationsByName.size() == 1, "Found more then one function in local registry");
-				definition = this.registrationsByName.keySet().iterator().next();
+				if (this.registrationsByName.size() > 0) {
+					Assert.isTrue(this.registrationsByName.size() == 1, "Found more then one function in local registry");
+					definition = this.registrationsByName.keySet().iterator().next();
+				}
 			}
 		}
 		return definition;