diff --git a/Languages/Smalltalk/ChangeLog b/Languages/Smalltalk/ChangeLog
index 0523332..3bccfe3 100644
--- a/Languages/Smalltalk/ChangeLog
+++ b/Languages/Smalltalk/ChangeLog
@@ -1,9 +1,15 @@
+2019-03-25  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+    * STSmalltalkScriptObject.m (forwardInvocation:):
+    Call super class implementation for unimplemented methods so that they
+    get reported as unimplemented rather than silently returning nil.
+
 2019-02-22  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
-	* GNUmakefile:
-	* NSDictionary+additions.h:
-	* NSDictionary+additions.m:
-	Implement Smalltalk collection protocol methods for NSDictionary.
+    * GNUmakefile:
+    * NSDictionary+additions.h:
+    * NSDictionary+additions.m:
+    Implement Smalltalk collection protocol methods for NSDictionary.
 
 2017-12-27  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
diff --git a/Languages/Smalltalk/STSmalltalkScriptObject.m b/Languages/Smalltalk/STSmalltalkScriptObject.m
index e1bb109..a436186 100644
--- a/Languages/Smalltalk/STSmalltalkScriptObject.m
+++ b/Languages/Smalltalk/STSmalltalkScriptObject.m
@@ -170,7 +170,13 @@
     }
 
     method = [script methodWithName:methodName];
-    
+    if (method == nil)
+    {
+        [pool release];
+        [super forwardInvocation:invocation];
+        return;
+    }
+
     count = [[invocation methodSignature] numberOfArguments];
 
     NSDebugLLog(@"STSending",