diff --git a/Jocaml.java b/Jocaml.java
index ef219c4..ffacb56 100644
--- a/Jocaml.java
+++ b/Jocaml.java
@@ -170,6 +170,14 @@ public class Jocaml {
             this.code = code;
             this.numArgs = numArgs;
         }
+
+        static {
+            for (int i = 0; i < CamlInst.values().length; i++) {
+                if (CamlInst.values()[i].code != i) {
+                    throw new RuntimeException("what");
+                }
+            }
+        }
     }
 
     private static class CodeOffset {
@@ -413,15 +421,13 @@ public class Jocaml {
             while (this.data.position() < this.data.capacity()) {
                 int op = this.data.getInt();
                 String rep = null;
-                for (CamlInst inst : CamlInst.values()) {
-                    if (inst.code == op) {
-                        rep = inst.name();
-                        for (int i = 0; i < inst.numArgs; i++) {
-                            rep += " " + this.data.getInt();
-                        }
+                try {
+                    CamlInst inst = CamlInst.values()[op];
+                    rep = inst.name();
+                    for (int i = 0; i < inst.numArgs; i++) {
+                        rep += " " + this.data.getInt();
                     }
-                }
-                if (rep == null) {
+                } catch (ArrayIndexOutOfBoundsException e) {
                     rep = "<UNKNOWN " + op + ">";
                 }
                 System.out.println(rep);