diff --git a/src/mudlib/zmachine/zlexer.py b/src/mudlib/zmachine/zlexer.py
index ad31417..378ea23 100644
--- a/src/mudlib/zmachine/zlexer.py
+++ b/src/mudlib/zmachine/zlexer.py
@@ -124,9 +124,13 @@ class ZLexer:
 
         token_list = self._tokenise_string(string, separators)
 
+        # Truncate to dictionary resolution (6 chars V1-3, 9 chars V4+)
+        max_word_len = 6 if self._memory.version <= 3 else 9
+
         final_list = []
         for word in token_list:
-            byte_addr = dict.get(word, 0)
+            lookup_key = word[:max_word_len]
+            byte_addr = dict.get(lookup_key, 0)
             final_list.append([word, byte_addr])
 
         return final_list