diff --git a/manticore/ethereum.py b/manticore/ethereum.py
index 3a89eb4..2023d54 100644
--- a/manticore/ethereum.py
+++ b/manticore/ethereum.py
@@ -230,7 +230,10 @@ class SolidityMetadata(object):
         else:
             srcmap = self.srcmap
 
-        beg, size, _, _ = srcmap[asm_offset]
+        try:
+            beg, size, _, _ = srcmap[asm_offset]
+        except KeyError:
+            return ''
 
         output = ''
         nl = self.source_code.count('\n')