diff --git a/dlls/oledb32/convert.c b/dlls/oledb32/convert.c
index 0d45ef064a00107509ab864d9ca2815ae8196eb5..4247723a757058d5b2c33fad1c718959433a08ba 100644
--- a/dlls/oledb32/convert.c
+++ b/dlls/oledb32/convert.c
@@ -1371,6 +1371,8 @@ static HRESULT WINAPI convert_GetConversionSize(IDataConvert* iface,
     if ((*dst_len = get_length(dst_type)))
         return S_OK;
 
+    *dst_len = 110;
+
     if(src_type == DBTYPE_VARIANT && V_VT((VARIANT*)src) == VT_NULL)
         return S_OK;
 
diff --git a/dlls/oledb32/tests/convert.c b/dlls/oledb32/tests/convert.c
index 8424442ea5ac21d6d5ac57b34cc54e507973bae9..9fee0241e60e334b33865ad47ad917d8c6cf14cf 100644
--- a/dlls/oledb32/tests/convert.c
+++ b/dlls/oledb32/tests/convert.c
@@ -2853,18 +2853,18 @@ static void test_getconversionsize(void)
     V_VT(&var) = VT_NULL;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_STR, NULL, &dst_len, &var);
     ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     V_VT(&var) = VT_NULL;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_WSTR, NULL, &dst_len, &var);
     ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     src_len = 20;
     V_VT(&var) = VT_NULL;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_VARIANT, DBTYPE_BYTES, &src_len, &dst_len, &var);
     ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
     VariantClear(&var);
 
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_NUMERIC, DBTYPE_NUMERIC, NULL, &dst_len, NULL);
@@ -2875,243 +2875,243 @@ static void test_getconversionsize(void)
     src_len = sizeof(i4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I4, DBTYPE_WSTR, &src_len, &dst_len, &i4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I4, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI4, DBTYPE_WSTR, &src_len, &dst_len, &i4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI4, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_WSTR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_WSTR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i1);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I1, DBTYPE_WSTR, &src_len, &dst_len, &i1);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I1, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_WSTR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(f4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_R4, DBTYPE_WSTR, &src_len, &dst_len, &f4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_R4, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i8);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI8, DBTYPE_WSTR, &src_len, &dst_len, &i8);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI8, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i8);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I8, DBTYPE_WSTR, &src_len, &dst_len, &i8);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I8, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(dbdate);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DATE, DBTYPE_WSTR, &src_len, &dst_len, &dbdate);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DATE, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(dec);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DECIMAL, DBTYPE_WSTR, &src_len, &dst_len, &dec);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DECIMAL, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_EMPTY, DBTYPE_WSTR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I4, DBTYPE_STR, &src_len, &dst_len, &i4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I4, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI4, DBTYPE_STR, &src_len, &dst_len, &i4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI4, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_STR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I2, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_STR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i1);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I1, DBTYPE_STR, &src_len, &dst_len, &i1);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I1, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i2);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_STR, &src_len, &dst_len, &i2);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI2, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(f4);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_R4, DBTYPE_STR, &src_len, &dst_len, &f4);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_R4, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i8);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI8, DBTYPE_STR, &src_len, &dst_len, &i8);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_UI8, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(i8);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I8, DBTYPE_STR, &src_len, &dst_len, &i8);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_I8, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(dbdate);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DATE, DBTYPE_STR, &src_len, &dst_len, &dbdate);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DATE, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     src_len = sizeof(dec);
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DECIMAL, DBTYPE_STR, &src_len, &dst_len, &dec);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_DECIMAL, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 
     dst_len = 0;
     hr = IDataConvert_GetConversionSize(convert, DBTYPE_EMPTY, DBTYPE_STR, NULL, &dst_len, NULL);
     todo_wine ok(hr == S_OK, "got 0x%08x\n", hr);
-    todo_wine ok(dst_len == 110, "%ld\n", dst_len);
+    ok(dst_len == 110, "%ld\n", dst_len);
 }
 
 static void test_converttobytes(void)