diff -r cf82769eb136 -r 4d0fff61d65e src/BytecodeCompiler.cpp
--- a/src/BytecodeCompiler.cpp	Sun Aug 05 15:38:52 2012 -0700
+++ b/src/BytecodeCompiler.cpp	Sun Aug 05 21:24:41 2012 -0700
@@ -25,6 +25,7 @@
 #include "Strings.h"
 #include "Zone.h"
 #include "Environments.h"
+#include "Box.h"
 #include "Heap-inl.h"
 
 using namespace ke;
@@ -839,9 +840,12 @@
         native = node->callee()->toNameProxy()->binding()->toNamedFunction();
     }
 
+    Local<Type> given(zone_);
     for (size_t i = node->arguments()->length() - 1; i < node->arguments()->length(); i--) {
         Expression *arg = node->arguments()->at(i);
 
+        given = arg->type();
+
         // We need to compute a reference if the parameter was in the form:
         //  f(&a)
         // Note this form does not allow: f({})
@@ -849,7 +853,6 @@
         // We also need to compute references for all variadic native
         // arguments, but arrays and references are already in the
         // appropriate form.
-        Local<Type> given(zone_, arg->type());
         bool mustPushReference = false;
         if (i >= funType->parameters()->length()) {
             assert(funType->isNative() && funType->isNativeVariadic());
@@ -892,14 +895,41 @@
         }
     }
 
+    unsigned argc = node->arguments()->length();
+
+    // If there are missing arguments, then we're not done and have to push
+    // default parameters.
+    Local<Box> box(zone_);
+    for (size_t i = node->arguments()->length(); i < funType->parameters()->length(); i++) {
+        box = Box::cast(funType->defaults()->at(i));
+
+        if (box->type()->isPod()) {
+            if (box->type()->pod() == PrimitiveType_Int32)
+                __ int_(box->toInt32());
+            else if (box->type()->pod() == PrimitiveType_Float)
+                __ float_(box->toFloat());
+            else
+                assert(false);
+        } else {
+            assert(false);
+        }
+
+        if (funType->parameterAt(i)->isReference()) {
+            __ note_position(node->pos());
+            __ slotref_lifo();
+        }
+
+        argc++;
+    }
+
     __ note_position(node->pos());
     if (native) {
-        __ callnative(native->slot(), node->arguments()->length());
-        __ drop(node->arguments()->length());
+        __ callnative(native->slot(), argc);
+        __ drop(argc);
     } else {
         node->callee()->accept(this);
         __ call(funType);
-        __ drop(node->arguments()->length() + 1);
+        __ drop(argc + 1);
     }
 }