diff --git a/src/disassembler.rs b/src/disassembler.rs
index f5cf1ce..eefeef0 100644
--- a/src/disassembler.rs
+++ b/src/disassembler.rs
@@ -54,6 +54,9 @@ impl DebugSymbols {
     }
 
     fn lookup_method_idx(&self, idx: usize) -> Option<String> {
+        if idx >= self.constants.len() {
+            return None;
+        }
         match self.methods.get(&self.constants[idx]) {
             Some(name) => Some(name.to_string()),
             None => None,