diff --git a/dlls/vbscript/interp.c b/dlls/vbscript/interp.c
index f582e8069e1..0c3470b7b94 100644
--- a/dlls/vbscript/interp.c
+++ b/dlls/vbscript/interp.c
@@ -53,6 +53,12 @@ typedef struct {
     } u;
 } ref_t;
 
+typedef struct {
+    VARIANT *v;
+    VARIANT store;
+    BOOL owned;
+} variant_val_t;
+
 static HRESULT lookup_identifier(exec_ctx_t *ctx, BSTR name, ref_t *ref)
 {
     named_item_t *item;
@@ -109,6 +115,35 @@ static void stack_popn(exec_ctx_t *ctx, unsigned n)
         VariantClear(stack_pop(ctx));
 }
 
+static HRESULT stack_pop_val(exec_ctx_t *ctx, variant_val_t *v)
+{
+    VARIANT *var;
+
+    var = stack_pop(ctx);
+
+    if(V_VT(var) == (VT_BYREF|VT_VARIANT)) {
+        v->owned = FALSE;
+        var = V_VARIANTREF(var);
+    }else {
+        v->owned = TRUE;
+    }
+
+    if(V_VT(var) == VT_DISPATCH) {
+        FIXME("got dispatch - get its default value\n");
+        return E_NOTIMPL;
+    }else {
+        v->v = var;
+    }
+
+    return S_OK;
+}
+
+static inline void release_val(variant_val_t *v)
+{
+    if(v->owned)
+        VariantClear(v->v);
+}
+
 static void vbstack_to_dp(exec_ctx_t *ctx, unsigned arg_cnt, DISPPARAMS *dp)
 {
     dp->cArgs = arg_cnt;
@@ -200,8 +235,22 @@ static HRESULT interp_string(exec_ctx_t *ctx)
 
 static HRESULT interp_not(exec_ctx_t *ctx)
 {
-    FIXME("\n");
-    return E_NOTIMPL;
+    variant_val_t val;
+    VARIANT v;
+    HRESULT hres;
+
+    TRACE("\n");
+
+    hres = stack_pop_val(ctx, &val);
+    if(FAILED(hres))
+        return hres;
+
+    hres = VarNot(val.v, &v);
+    release_val(&val);
+    if(FAILED(hres))
+        return hres;
+
+    return stack_push(ctx, &v);
 }
 
 static const instr_func_t op_funcs[] = {
diff --git a/dlls/vbscript/tests/lang.vbs b/dlls/vbscript/tests/lang.vbs
index 32fc903517f..8f13c9c42ea 100644
--- a/dlls/vbscript/tests/lang.vbs
+++ b/dlls/vbscript/tests/lang.vbs
@@ -22,4 +22,7 @@ call ok(true, "true is not true?")
 ok true, "true is not true?"
 call ok((true), "true is not true?")
 
+ok not false, "not false but not true?"
+ok not not true, "not not true but not true?"
+
 reportSuccess()