diff --git a/src/vm/wren_vm.c b/src/vm/wren_vm.c
index bac89fe0..55cd2cae 100644
--- a/src/vm/wren_vm.c
+++ b/src/vm/wren_vm.c
@@ -366,6 +366,7 @@ static void bindMethod(WrenVM* vm, int methodType, int symbol,
 static void callForeign(WrenVM* vm, ObjFiber* fiber,
                         WrenForeignMethodFn foreign, int numArgs)
 {
+  Value* oldApiStack = vm->apiStack; /// save the current state so we can restore it when done
   vm->apiStack = fiber->stackTop - numArgs;
 
   foreign(vm);
@@ -373,7 +374,7 @@ static void callForeign(WrenVM* vm, ObjFiber* fiber,
   // Discard the stack slots for the arguments and temporaries but leave one
   // for the result.
   fiber->stackTop = vm->apiStack + 1;
-  vm->apiStack = NULL;
+  vm->apiStack = oldApiStack; /// restore apiStack to value prior to calling foreign method
 }
 
 // Handles the current fiber having aborted because of an error. Switches to
@@ -655,11 +656,12 @@ static void createForeign(WrenVM* vm, ObjFiber* fiber, Value* stack)
   ASSERT(method->type == METHOD_FOREIGN, "Allocator should be foreign.");
 
   // Pass the constructor arguments to the allocator as well.
+  Value* oldApiStack = vm->apiStack;
   vm->apiStack = stack;
 
   method->fn.foreign(vm);
 
-  vm->apiStack = NULL;
+  vm->apiStack = oldApiStack;
   // TODO: Check that allocateForeign was called.
 }