diff --git a/modules/rostests/apitests/user32/CMakeLists.txt b/modules/rostests/apitests/user32/CMakeLists.txt
index 2ee5e76b815..4ab323f327c 100644
--- a/modules/rostests/apitests/user32/CMakeLists.txt
+++ b/modules/rostests/apitests/user32/CMakeLists.txt
@@ -15,6 +15,7 @@ list(APPEND SOURCE
     desktop.c
     EmptyClipboard.c
     EnumDisplaySettings.c
+    GetClassInfo.c
     GetDCEx.c
     GetIconInfo.c
     GetKeyState.c
diff --git a/modules/rostests/apitests/user32/GetClassInfo.c b/modules/rostests/apitests/user32/GetClassInfo.c
new file mode 100644
index 00000000000..37862c5d1db
--- /dev/null
+++ b/modules/rostests/apitests/user32/GetClassInfo.c
@@ -0,0 +1,170 @@
+/*
+ * PROJECT:     ReactOS api tests
+ * LICENSE:     GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
+ * PURPOSE:     Tests for GetClassInfo
+ * COPYRIGHT:   Copyright 2023 Timo Kreuzer <timo.kreuzer@reactos.org>
+ */
+
+#include "precomp.h"
+
+static USHORT GetWinVersion(VOID)
+{
+    return ((GetVersion() & 0xFF) << 8) |
+        ((GetVersion() >> 8) & 0xFF);
+}
+
+VOID Test_Desktop(VOID)
+{
+    WNDCLASSEXW wcex;
+    BOOL result;
+
+    memset(&wcex, 0xab, sizeof(wcex));
+
+    result = GetClassInfoExW(GetModuleHandle(NULL), (LPCWSTR)WC_DESKTOP, &wcex);
+    ok_int(result, (ULONG_PTR)WC_DESKTOP);
+
+    ok_hex(wcex.cbSize, 0xabababab);
+    ok_hex(wcex.style, 0x8);
+    ok(wcex.lpfnWndProc != NULL, "lpfnWndProc shound't be NULL\n");
+    ok_int(wcex.cbClsExtra, 0);
+    ok_int(wcex.cbWndExtra, GetWinVersion() <= 0x502 ? 8 : 0);
+    ok_ptr(wcex.hInstance, GetModuleHandle(NULL));
+    ok_ptr(wcex.hIcon, NULL);
+    ok(wcex.hCursor != NULL, "hCursor shound't be NULL\n");
+    if (GetWinVersion() > 0x502)
+        ok_ptr(wcex.hbrBackground, (HBRUSH)(ULONG_PTR)2);
+    else
+        ok(wcex.hbrBackground != NULL, "hbrBackground shound't be NULL\n");
+    ok_ptr(wcex.lpszMenuName, NULL);
+    ok_ptr(wcex.lpszClassName, (LPCWSTR)WC_DESKTOP);
+    ok_ptr(wcex.hIconSm, NULL);
+}
+
+VOID Test_Dialog(VOID)
+{
+    WNDCLASSEXW wcex;
+    BOOL result;
+
+    memset(&wcex, 0xab, sizeof(wcex));
+
+    result = GetClassInfoExW(GetModuleHandle(NULL), (LPCWSTR)(ULONG_PTR)WC_DIALOG, &wcex);
+    ok_int(result, (ULONG_PTR)WC_DIALOG);
+    
+    ok_hex(wcex.cbSize, 0xabababab);
+    ok_hex(wcex.style, 0x808);
+    ok(wcex.lpfnWndProc != NULL, "lpfnWndProc shound't be NULL\n");
+    ok_int(wcex.cbClsExtra, 0);
+    ok_int(wcex.cbWndExtra, 30); // DLGWINDOWEXTRA
+    ok_ptr(wcex.hInstance, GetModuleHandle(NULL));
+    ok_ptr(wcex.hIcon, NULL);
+    ok(wcex.hCursor != NULL, "hCursor shound't be NULL\n");
+    ok_ptr(wcex.hbrBackground, NULL);
+    ok_ptr(wcex.lpszMenuName, NULL);
+    ok_ptr(wcex.lpszClassName, (LPCWSTR)(ULONG_PTR)WC_DIALOG);
+    ok_ptr(wcex.hIconSm, NULL);
+}
+
+VOID Test_Menu(VOID)
+{
+    WNDCLASSEXW wcex;
+    BOOL result;
+
+    memset(&wcex, 0xab, sizeof(wcex));
+
+    result = GetClassInfoExW(GetModuleHandle(NULL), (LPCWSTR)(ULONG_PTR)WC_MENU, &wcex);
+    ok_int(result, (ULONG_PTR)WC_MENU);
+
+    ok_hex(wcex.cbSize, 0xabababab);
+    ok_hex(wcex.style, 0x803);
+    ok_ptr(wcex.lpfnWndProc, NULL);
+    ok_int(wcex.cbClsExtra, 0);
+    ok_int(wcex.cbWndExtra, 16);
+    ok_ptr(wcex.hInstance, GetModuleHandle(NULL));
+    ok_ptr(wcex.hIcon, NULL);
+    ok(wcex.hCursor != NULL, "hCursor shound't be NULL\n");
+    ok_ptr(wcex.hbrBackground, NULL);
+    ok_ptr(wcex.lpszMenuName, NULL);
+    ok_ptr(wcex.lpszClassName, (LPCWSTR)(ULONG_PTR)WC_MENU);
+    ok_ptr(wcex.hIconSm, NULL);
+}
+
+
+VOID Test_SwitchWnd(VOID)
+{
+    WNDCLASSEXW wcex;
+    BOOL result;
+
+    memset(&wcex, 0xab, sizeof(wcex));
+
+    result = GetClassInfoExW(GetModuleHandle(NULL), (LPCWSTR)(ULONG_PTR)WC_SWITCH, &wcex);
+    ok_int(result, (ULONG_PTR)WC_SWITCH);
+
+    ok_hex(wcex.cbSize, 0xabababab);
+    ok_hex(wcex.style, 0x803);
+    ok_ptr(wcex.lpfnWndProc, NULL);
+    ok_int(wcex.cbClsExtra, 0);
+    ok_int(wcex.cbWndExtra, GetWinVersion() <= 0x502 ? sizeof(ULONG_PTR) : 16);
+    ok_ptr(wcex.hInstance, GetModuleHandle(NULL));
+    ok_ptr(wcex.hIcon, NULL);
+    ok(wcex.hCursor != NULL, "hCursor shound't be NULL\n");
+    ok_ptr(wcex.hbrBackground, NULL);
+    ok_ptr(wcex.lpszMenuName, NULL);
+    ok_ptr(wcex.lpszClassName, (LPCWSTR)(ULONG_PTR)WC_SWITCH);
+    ok_ptr(wcex.hIconSm, NULL);
+}
+
+VOID Test_Custom(VOID)
+{
+    WNDCLASSEXW wcex;
+    ATOM atom;
+    BOOL result;
+
+    memset(&wcex, 0, sizeof(wcex));
+
+    wcex.cbSize = sizeof(WNDCLASSEXW);
+    wcex.style = 0x1;
+    wcex.lpfnWndProc = DefWindowProcW;
+    wcex.cbClsExtra = 1;
+    wcex.cbWndExtra = 5;
+    wcex.hInstance = GetModuleHandle(NULL);
+    wcex.hIcon = NULL;
+    wcex.hCursor = NULL;
+    wcex.hbrBackground = NULL;
+    wcex.lpszMenuName = NULL;
+    wcex.lpszClassName = L"ProTestClass1";
+    wcex.hIconSm = 0;
+
+    atom = RegisterClassExW(&wcex);
+    ok(atom != 0, "Failed to register class!\n");
+    if (atom == 0)
+    {
+        skip("Failed to register class!");
+        return;
+    }
+
+    memset(&wcex, 0xab, sizeof(wcex));
+
+    result = GetClassInfoExW(GetModuleHandle(NULL), (LPCWSTR)(ULONG_PTR)atom, &wcex);
+    ok_int(result, atom);
+
+    ok_hex(wcex.cbSize, 0xabababab);
+    ok_hex(wcex.style, 0x1);
+    ok_ptr(wcex.lpfnWndProc, DefWindowProcW);
+    ok_int(wcex.cbClsExtra, 1);
+    ok_int(wcex.cbWndExtra, 5);
+    ok_ptr(wcex.hInstance, GetModuleHandle(NULL));
+    ok_ptr(wcex.hIcon, NULL);
+    ok_ptr(wcex.hIcon, NULL);
+    ok_ptr(wcex.hbrBackground, NULL);
+    ok_ptr(wcex.lpszMenuName, NULL);
+    ok_ptr(wcex.lpszClassName, (LPCWSTR)(ULONG_PTR)atom);
+    ok_ptr(wcex.hIconSm, NULL);
+}
+
+START_TEST(GetClassInfo)
+{
+    Test_Desktop();
+    Test_Dialog();
+    Test_SwitchWnd();
+    Test_Custom();
+}
diff --git a/modules/rostests/apitests/user32/testlist.c b/modules/rostests/apitests/user32/testlist.c
index 9b351182afb..ee6f6970d76 100644
--- a/modules/rostests/apitests/user32/testlist.c
+++ b/modules/rostests/apitests/user32/testlist.c
@@ -17,6 +17,7 @@ extern void func_DrawText(void);
 extern void func_desktop(void);
 extern void func_EmptyClipboard(void);
 extern void func_EnumDisplaySettings(void);
+extern void func_GetClassInfo(void);
 extern void func_GetDCEx(void);
 extern void func_GetIconInfo(void);
 extern void func_GetKeyState(void);
@@ -73,6 +74,7 @@ const struct test winetest_testlist[] =
     { "desktop", func_desktop },
     { "EmptyClipboard", func_EmptyClipboard },
     { "EnumDisplaySettings", func_EnumDisplaySettings },
+    { "GetClassInfo", func_GetClassInfo },
     { "GetDCEx", func_GetDCEx },
     { "GetIconInfo", func_GetIconInfo },
     { "GetKeyState", func_GetKeyState },
diff --git a/modules/rostests/apitests/win32nt/ntuser/NtUserGetClassInfo.c b/modules/rostests/apitests/win32nt/ntuser/NtUserGetClassInfo.c
index 1e2a8a79265..65002ced27a 100644
--- a/modules/rostests/apitests/win32nt/ntuser/NtUserGetClassInfo.c
+++ b/modules/rostests/apitests/win32nt/ntuser/NtUserGetClassInfo.c
@@ -14,6 +14,11 @@ START_TEST(NtUserGetClassInfo)
     UNICODE_STRING us;
     PWSTR pwstr = NULL;
 
+#ifdef _M_AMD64
+    skip("Test is broken on x64.\n");
+    return;
+#endif
+
     us.Length = 8;
     us.MaximumLength = 8;
     us.Buffer = L"test";