diff --git a/lang/boolean.c b/lang/boolean.c
index eab6ca0..b031635 100644
--- a/lang/boolean.c
+++ b/lang/boolean.c
@@ -33,7 +33,7 @@
 	return boolean->value;
 }
 
-static void boolean_invert(VmState state, Object obj, void *priv) {
+static void boolean_invert(VmState state, Object obj, int priv) {
 	(void)priv;
 	int arg_count = vm_stack_depth(state);
 	vm_abort_if(state, arg_count != 1,
@@ -44,7 +44,7 @@
 }
 
 static struct object_call calls[] = {
-	{.name = "Invert", .handler = boolean_invert, .priv = NULL},
+	{.name = "Invert", .handler = boolean_invert, .priv = 0},
 	{.name = NULL, /* end */}};
 
 static struct object_class boolean_class = {
diff --git a/lang/compile.py b/lang/compile.py
index fc19ad9..2f9f388 100755
--- a/lang/compile.py
+++ b/lang/compile.py
@@ -980,30 +980,38 @@
 static void CLASSNAME_cleanup(VmState state, Object obj) {
 	struct object_list **args = (struct object_list **)object_priv(state, obj, &CLASSNAME_class);
 	free_args(state, args);
-}
-
-static void CLASSNAME_call_bytecode(VmState state, Object obj, void *priv) {
-	struct object_list **args = (struct object_list **)object_priv(state, obj, &CLASSNAME_class);
-	bytecode_run(state, obj, (const unsigned char *)priv, *args);
 }"""
 
-def generate_class_call(class_name, func_name):
-	call = '{.name = "%s", .handler = CLASSNAME_call_bytecode, ' % (func_name)
-	call += '\n\t\t.priv = (void *)bytecode_%s_%s },\n\t' % (class_name, func_name)
+def generate_class_call(class_name, func_name, index):
+	call = '{.name = "%s", .handler = CLASSNAME_call_bytecode, .priv = %s },\n\t' % (func_name, index)
 	return call
 
 def generate_class_structs(class_ir):
 	calls = ""
+	bytecodes = ""
+	index = 0
 	for func in class_ir.functions:
-		calls += generate_class_call(class_ir.name, func)
-	return """static struct object_call CLASSNAME_calls[] = {
+		calls += generate_class_call(class_ir.name, func, index)
+		bytecodes += "bytecode_%s_%s,\n\t" % (class_ir.name, func)
+		index += 1
+	return """static const unsigned char *CLASSNAME_bytecodes[] = {
+	%sNULL,
+};
+
+static void CLASSNAME_call_bytecode(VmState state, Object obj, int priv) {
+	struct object_list **args = (struct object_list **)object_priv(state, obj, &CLASSNAME_class);
+	const unsigned char *bytecode = CLASSNAME_bytecodes[priv];
+	bytecode_run(state, obj, bytecode, *args);
+}
+
+static struct object_call CLASSNAME_calls[] = {
 	%s{.name = NULL, /* end */ },
 };
 
 static struct object_class CLASSNAME_class = {
 	.cleanup = CLASSNAME_cleanup,
 	.calls = &CLASSNAME_calls[0],
-};""" % (calls)
+};""" % (bytecodes, calls)
 
 def generate_c_class(class_ir):
 	functions = []
diff --git a/lang/object.h b/lang/object.h
index ebc16a2..1ff70bf 100644
--- a/lang/object.h
+++ b/lang/object.h
@@ -9,8 +9,8 @@
 // Dispatchable object call
 struct object_call {
 	const char *name;
-	void (*handler)(VmState state, Object obj, void *priv);
-	void *priv;
+	void (*handler)(VmState state, Object obj, int priv);
+	int priv;
 };
 
 // Object class shared between objects
diff --git a/lang/rational.c b/lang/rational.c
index 47247eb..9c27d60 100644
--- a/lang/rational.c
+++ b/lang/rational.c
@@ -57,12 +57,12 @@
 	return &ratio->value;
 }
 
-#define OP_ADD (void *)1
-#define OP_SUBTRACT (void *)2
-#define OP_DIVIDE (void *)3
-#define OP_MULTIPLY (void *)4
+#define OP_ADD 1
+#define OP_SUBTRACT 2
+#define OP_DIVIDE 3
+#define OP_MULTIPLY 4
 
-static void rational_math(VmState state, Object obj, void *priv) {
+static void rational_math(VmState state, Object obj, int priv) {
 	int arg_count = vm_stack_depth(state);
 	vm_abort_if(state, arg_count != 2,
 		"rational_math called without 2 arguments");
@@ -87,7 +87,7 @@
 	mpq_clear(result);
 }
 
-static void rational_equals(VmState state, Object obj, void *priv) {
+static void rational_equals(VmState state, Object obj, int priv) {
 	(void)priv;
 	int arg_count = vm_stack_depth(state);
 	vm_abort_if(state, arg_count != 2,
@@ -105,7 +105,7 @@
 	{.name = "Subtract", .handler = rational_math, .priv = OP_SUBTRACT},
 	{.name = "Divide", .handler = rational_math, .priv = OP_DIVIDE},
 	{.name = "Multiply", .handler = rational_math, .priv = OP_MULTIPLY},
-	{.name = "Equals", .handler = rational_equals, .priv = NULL},
+	{.name = "Equals", .handler = rational_equals, .priv = 0},
 	{.name = NULL, /* end */}};
 
 static struct object_class ratio_class = {