diff -r 970abfc9f077 -r b029d63565a2 src/BytecodeCompiler.cpp
--- a/src/BytecodeCompiler.cpp	Sun Sep 16 23:33:48 2012 -0700
+++ b/src/BytecodeCompiler.cpp	Mon Sep 17 00:10:01 2012 -0700
@@ -530,6 +530,18 @@
         break;
       }
 
+      case TOK_SIZEOF:
+      {
+        Local<Type> type(zone_, node->expression()->type());
+        if (type->isFixedLength()) {
+            __ int_(type->fixedLength());
+        } else {
+            node->expression()->accept(this);
+            __ sizeof_();
+        }
+        break;
+      }
+
       default:
         assert(node->token() == TOK_TILDE);
         node->expression()->accept(this);