diff --git a/lib/compiler.c b/lib/compiler.c
index e745f46..b3024c4 100644
--- a/lib/compiler.c
+++ b/lib/compiler.c
@@ -413,9 +413,9 @@ int compiler_run(compiler_t* compiler, node_t* node, program_t* program)
 
         fun->arg_base = *compiler->id;
 
-        compiler_run(&comp, (node_t*) node->children.data[1], &fun->program);
-        compiler_run(&comp, (node_t*) node->children.data[2], &fun->program);
-        program_push_instr(&fun->program, OP_RET, RZ_NO_PARAM);
+        compiler_run(&comp, (node_t*) node->children.data[1], fun->program);
+        compiler_run(&comp, (node_t*) node->children.data[2], fun->program);
+        program_push_instr(fun->program, OP_RET, RZ_NO_PARAM);
 
         prepass_free(&pre);
         tysolver_free(&tysolver);
diff --git a/lib/fun.c b/lib/fun.c
index 63eab5f..7ed1795 100644
--- a/lib/fun.c
+++ b/lib/fun.c
@@ -6,7 +6,9 @@
 void fun_init(fun_t* fun, struct tysy* tysy, err_t* err)
 {
   assert(fun);
-  program_init(&fun->program);
+  fun->program = malloc(sizeof(program_t));
+  program_init(fun->program);
+
   fun->err = err;
   fun->sym = malloc(sizeof(sym_t));
   sym_init((sym_t*) fun->sym, (tysy_t*) tysy, err);
@@ -34,6 +36,10 @@ fun_t* fun_new_clone(fun_t* fun)
   clone->base = fun->base;
   clone->arg_base = fun->arg_base;
 
+  program_free(clone->program);
+  free(clone->program);
+  clone->program = program_new_clone(fun->program);
+
   for (size_t i=0; i<fun->closure.size; i++)
     {
       fun_capture(clone,
@@ -47,7 +53,10 @@ fun_t* fun_new_clone(fun_t* fun)
 void fun_free(fun_t* fun)
 {
   assert(fun);
-  program_free(&fun->program);
+
+  program_free(fun->program);
+  free(fun->program);
+  fun->program = NULL;
 
   sym_free((sym_t*) fun->sym);
   free(fun->sym);
diff --git a/lib/fun.h b/lib/fun.h
index a498c30..b4d993d 100644
--- a/lib/fun.h
+++ b/lib/fun.h
@@ -15,7 +15,7 @@ typedef struct {
 } closure_entry_t;
 
 typedef struct {
-  program_t program;
+  program_t* program;
   err_t* err;
   struct sym* sym;
   struct tysy* tysy;
diff --git a/lib/heap.c b/lib/heap.c
index f355c72..87522bf 100644
--- a/lib/heap.c
+++ b/lib/heap.c
@@ -13,8 +13,8 @@ void heap_free(heap_t* heap)
 {
   for (size_t i=0; i<heap->size; i++)
     {
-      //value_free(heap->data[i]);
-      //free(heap->data[i]);
+      value_free(heap->data[i]);
+      free(heap->data[i]);
     }
 
   free(heap->data);
diff --git a/lib/program.c b/lib/program.c
index de08a74..e29439f 100644
--- a/lib/program.c
+++ b/lib/program.c
@@ -15,6 +15,32 @@ void program_init(program_t* program)
   program->values.data = NULL;
 }
 
+program_t* program_new_clone(program_t* program)
+{
+  assert(program);
+
+  program_t* clone = malloc(sizeof(program_t));
+  program_init(clone);
+
+  for (size_t i=0; i<program->size; i++)
+    {
+      program_push_instr(clone,
+                         program->ops[i],
+                         program->params[i]);
+
+    }
+
+  for (size_t i=0; i<program->values.size; i++)
+    {
+      char m[512]; value_str(program->values.data[i], m, 512);
+
+      program_push_new_value(clone,
+                             value_new_clone(program->values.data[i]));
+    }
+
+  return clone;
+}
+
 void program_free(program_t* program)
 {
   assert(program);
diff --git a/lib/program.h b/lib/program.h
index 88ad1b2..6f35b51 100644
--- a/lib/program.h
+++ b/lib/program.h
@@ -21,6 +21,7 @@ typedef struct {
 } program_t;
 
 void program_init(program_t* program);
+program_t* program_new_clone(program_t* program);
 void program_free(program_t* program);
 
 size_t program_push_instr(program_t* program, Opcode op, param_t param);
diff --git a/lib/value.c b/lib/value.c
index ea5af6b..3ac7da4 100644
--- a/lib/value.c
+++ b/lib/value.c
@@ -18,17 +18,32 @@ value_t* value_new_clone(value_t* value)
   value_t* clone = malloc(sizeof(value_t));
   value_init(clone, value->type, value->line);
 
-  clone->value = value->value;
-
   if (value->type->kind == TYPE_STR)
     {
       clone->value.str = strdup(value->value.str);
     }
-
-  if (value->type->kind == TYPE_FUN)
+  else if (value->type->kind == TYPE_NUM)
+    {
+      clone->value.num = value->value.num;
+    }
+  else if (value->type->kind == TYPE_FUN)
     {
       clone->value.fun = fun_new_clone(value->value.fun);
     }
+  else if (value->type->kind == TYPE_REF)
+    {
+      clone->value.ref = value->value.ref;
+    }
+  else if (value->type->kind == TYPE_BOOL)
+    {
+      clone->value.bool = value->value.bool;
+    }
+  else
+    {
+      fprintf(stderr, "Cannot clone value of unknown type '%s'.",
+              TypeKindStr[value->type->kind]);
+      abort();
+    }
 
   return clone;
 }
diff --git a/lib/vm.c b/lib/vm.c
index 82a20a3..d6be6a4 100644
--- a/lib/vm.c
+++ b/lib/vm.c
@@ -86,7 +86,7 @@ void vm_frame_push(vm_t* vm, fun_t* fun)
 
   if (fun != NULL)
     {
-      frame->program = &fun->program;
+      frame->program = fun->program;
       frame->locals = (locals_t*) fun->locals;
     }
   else
@@ -103,8 +103,6 @@ int vm_frame_pop(vm_t* vm)
 
   if (vm->top_frame->fun)
     {
-      fun_free(vm->top_frame->fun);
-      free(vm->top_frame->fun);
       vm->top_frame->fun = NULL;
     }
 
@@ -120,6 +118,7 @@ int vm_frame_pop(vm_t* vm)
 
       vm_frame_free(vm->top_frame);
       free(vm->top_frame);
+      vm->top_frame = NULL;
 
       vm->top_frame = prev;
 
@@ -487,7 +486,6 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
 
       if (vm->top_frame->fun)
         {
-
           fun_t* fun = vm->top_frame->fun;
 
           closure_entry_t* closure = fun_try_find_closure(fun, param);
@@ -508,7 +506,9 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
     } break;
 
     case OP_MKFUN: {
-      value_t* value = vm_pop(vm);
+      value_t* value = value_new_clone(vm_pop(vm));
+
+      assert(value->type->kind == TYPE_FUN);
       size_t addr = heap_alloc(&vm->heap, value);
 
       value_t* ref = tysy_new_ref(vm->tysy, addr, value->line);
@@ -518,7 +518,9 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
       locals_t* loc = &vm->locals;
 
       assert(value->type->kind == TYPE_FUN);
+
       fun_t* fun = value->value.fun;
+      frame_t* frame = vm->top_frame;
 
       if (vm->top_frame->fun)
         {
@@ -527,18 +529,20 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
       else if (prev && prev->fun)
         {
           loc = (locals_t*) prev->fun->locals;
+          frame = prev;
         }
       else if (prev)
         {
           loc = prev->locals;
+          frame = prev;
         }
 
       if (loc)
         {
           for (size_t i=0; i<loc->size; i++)
             {
-              int id = vm->top_frame->locals->data[i]->id;
-              value_t* loc_val = vm->top_frame->stack[addr];
+              int id = frame->locals->data[i]->id;
+              value_t* loc_val = frame->stack[loc->data[i]->addr];
 
               fun_capture(fun, id, loc_val);
             }
@@ -571,10 +575,12 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
         }
 
       value_t* fun_val = heap_deref(&vm->heap, fun_ref->value.ref);
+      assert(fun_val);
 
       assert(fun_val->type->kind == TYPE_FUN);
 
-      fun_t* fun = fun_new_clone(fun_val->value.fun);
+      assert(fun_val->value.fun);
+      fun_t* fun = fun_val->value.fun;
 
       vm->top_frame->pc++;
       vm_frame_push(vm, fun);
@@ -595,6 +601,7 @@ int vm_exec_instr(vm_t* vm, Opcode op, param_t param)
                        vm->top_frame->sp - 1);
         }
 
+
     } break;
 
     case OP_RET: {
diff --git a/tests/acceptances/fun.roza b/tests/acceptances/fun.roza
index 51a2a5d..bef14aa 100644
--- a/tests/acceptances/fun.roza
+++ b/tests/acceptances/fun.roza
@@ -1,14 +1,14 @@
 # FUNCTIONS
 # =========
 fun double(n)
-  n * 2
+  return n * 2
 end
 
 assert double(4) == 8
 assert 8 == double(4)
 
-assert double(4) != 10
-assert 9 != double(4)
+assert (double(4) == 10) == false
+assert (9 == double(4)) == false
 
 assert double(double(double(3))) == 24