diff --git a/dll/ntdll/ldr/ldrutils.c b/dll/ntdll/ldr/ldrutils.c
index 69e2f8c152e..1c67c8dccd4 100644
--- a/dll/ntdll/ldr/ldrutils.c
+++ b/dll/ntdll/ldr/ldrutils.c
@@ -2455,6 +2455,7 @@ LdrpLoadDll(IN BOOLEAN Redirected,
     RtlCopyUnicodeString(&RawDllName, DllName);
 
     /* Find the extension, if present */
+    /* NOTE: Access violation is expected here in some cases (Buffer[-1]) */
     p = DllName->Buffer + DllName->Length / sizeof(WCHAR) - 1;
     GotExtension = FALSE;
     while (p >= DllName->Buffer)
diff --git a/modules/rostests/apitests/ntdll/CMakeLists.txt b/modules/rostests/apitests/ntdll/CMakeLists.txt
index abda236e613..cc4adfac82f 100644
--- a/modules/rostests/apitests/ntdll/CMakeLists.txt
+++ b/modules/rostests/apitests/ntdll/CMakeLists.txt
@@ -7,6 +7,7 @@ spec2def(ntdll_apitest.exe ntdll_apitest.spec)
 
 list(APPEND SOURCE
     LdrEnumResources.c
+    LdrLoadDll.c
     load_notifications.c
     locale.c
     NtAcceptConnectPort.c
diff --git a/modules/rostests/apitests/ntdll/LdrLoadDll.c b/modules/rostests/apitests/ntdll/LdrLoadDll.c
new file mode 100644
index 00000000000..a84a5617771
--- /dev/null
+++ b/modules/rostests/apitests/ntdll/LdrLoadDll.c
@@ -0,0 +1,201 @@
+/*
+ * PROJECT:     ReactOS API Tests
+ * LICENSE:     LGPL-2.0-or-later (https://spdx.org/licenses/LGPL-2.0-or-later)
+ * PURPOSE:     Test for LdrLoadDll
+ * COPYRIGHT:   Copyright 2017 Thomas Faber <thomas.faber@reactos.org>
+ *              Copyright 2024 Katayama Hirofumi MZ <katayama.hirofumi.mz@gmail.com>
+ */
+
+#include "precomp.h"
+
+/*
+
+NTSTATUS
+NTAPI
+LdrLoadDll(
+    IN PWSTR SearchPath OPTIONAL,
+    IN PULONG DllCharacteristics OPTIONAL,
+    IN PUNICODE_STRING DllName,
+    OUT PVOID *BaseAddress
+);
+
+*/
+
+START_TEST(LdrLoadDll)
+{
+    NTSTATUS Status = STATUS_SUCCESS;
+    UNICODE_STRING DllName;
+    PVOID BaseAddress, BaseAddress2;
+    WCHAR szWinDir[MAX_PATH], szSysDir[MAX_PATH], szPath[MAX_PATH];
+    WCHAR *pch;
+
+    RtlInitEmptyUnicodeString(&DllName, NULL, 0);
+    GetWindowsDirectoryW(szWinDir, _countof(szWinDir));
+    GetSystemDirectoryW(szSysDir, _countof(szSysDir));
+
+    Status = 0xDEADFACE;
+    StartSeh()
+        Status = LdrLoadDll(NULL, NULL, &DllName, NULL);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(NULL, NULL, &DllName, &BaseAddress);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+    ok_ptr(BaseAddress, InvalidPointer);
+
+    Status = 0xDEADFACE;
+    StartSeh()
+        Status = LdrLoadDll(L"", NULL, &DllName, NULL);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(L"", NULL, &DllName, &BaseAddress);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+    ok_ptr(BaseAddress, InvalidPointer);
+
+    RtlInitUnicodeString(&DllName, L"advapi32.dll");
+
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(NULL, NULL, &DllName, NULL);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+    ok_ptr(BaseAddress, InvalidPointer);
+
+    RtlInitUnicodeString(&DllName, L"advapi32.dll");
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        BaseAddress = InvalidPointer;
+        Status = LdrLoadDll(NULL, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        ok(BaseAddress != NULL && BaseAddress != InvalidPointer, "BaseAddress = %p\n", BaseAddress);
+        if (NT_SUCCESS(Status))
+        {
+            BaseAddress2 = InvalidPointer;
+            Status = LdrLoadDll(NULL, NULL, &DllName, &BaseAddress2);
+            ok_ntstatus(Status, STATUS_SUCCESS);
+            ok_ptr(BaseAddress2, BaseAddress);
+            LdrUnloadDll(BaseAddress);
+        }
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    RtlInitUnicodeString(&DllName, L"advapi32.dll");
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(L"\\SystemRoot\\System32", NULL, &DllName, NULL);
+    EndSeh(STATUS_ACCESS_VIOLATION);
+    ok_ntstatus(Status, 0xDEADFACE);
+    ok_ptr(BaseAddress, InvalidPointer);
+
+    /* Test with only backslashes in path; no file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s\\advapi32", szSysDir);
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    /* Test with only backslashes in path; with file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s\\advapi32.dll", szSysDir);
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    /* Test with one forward slash in path; no file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s/advapi32", szSysDir);
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    /* Test with one forward slash in path; with file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s/advapi32.dll", szSysDir);
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    /* Test with only forward slashes in path; no file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s\\advapi32", szSysDir);
+    for (pch = szPath; *pch != UNICODE_NULL; ++pch)
+    {
+        if (*pch == L'\\')
+            *pch = L'/';
+    }
+
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+
+    /* Test with only forward slashes in path; with file extension */
+    /* Test with only forward slashes in path; with file extension */
+    StringCchPrintfW(szPath, _countof(szPath), L"%s\\advapi32.dll", szSysDir);
+    for (pch = szPath; *pch != UNICODE_NULL; ++pch)
+    {
+        if (*pch == L'\\')
+            *pch = L'/';
+    }
+
+    RtlInitUnicodeString(&DllName, szPath);
+    Status = 0xDEADFACE;
+    BaseAddress = InvalidPointer;
+    StartSeh()
+        Status = LdrLoadDll(szWinDir, NULL, &DllName, &BaseAddress);
+        ok_ntstatus(Status, STATUS_SUCCESS);
+        if (NT_SUCCESS(Status))
+            LdrUnloadDll(BaseAddress);
+    EndSeh(STATUS_SUCCESS);
+    ok_ntstatus(Status, STATUS_SUCCESS);
+    ok(BaseAddress != NULL, "BaseAddress was NULL\n");
+}
diff --git a/modules/rostests/apitests/ntdll/testlist.c b/modules/rostests/apitests/ntdll/testlist.c
index f837fa29f8f..10cc0d987da 100644
--- a/modules/rostests/apitests/ntdll/testlist.c
+++ b/modules/rostests/apitests/ntdll/testlist.c
@@ -4,6 +4,7 @@
 #include <apitest.h>
 
 extern void func_LdrEnumResources(void);
+extern void func_LdrLoadDll(void);
 extern void func_load_notifications(void);
 extern void func_NtAcceptConnectPort(void);
 extern void func_NtAccessCheck(void);
@@ -106,6 +107,7 @@ extern void func_UserModeException(void);
 const struct test winetest_testlist[] =
 {
     { "LdrEnumResources",               func_LdrEnumResources },
+    { "LdrLoadDll",                     func_LdrLoadDll },
     { "load_notifications",             func_load_notifications },
     { "NtAcceptConnectPort",            func_NtAcceptConnectPort },
     { "NtAccessCheck",                  func_NtAccessCheck },