diff --git a/modules/rostests/apitests/ntdll/NtApphelpCacheControl.c b/modules/rostests/apitests/ntdll/NtApphelpCacheControl.c
index ea9cb2920ce..d0ffde08809 100644
--- a/modules/rostests/apitests/ntdll/NtApphelpCacheControl.c
+++ b/modules/rostests/apitests/ntdll/NtApphelpCacheControl.c
@@ -15,6 +15,7 @@ enum ServiceCommands
     RegisterShimCacheWithoutHandle = 129,
 };
 
+static NTSTATUS (NTAPI *pNtApphelpCacheControl)(APPHELPCACHESERVICECLASS, PAPPHELP_CACHE_SERVICE_LOOKUP);
 
 NTSTATUS CallCacheControl(UNICODE_STRING* PathName, BOOLEAN WithMapping, APPHELPCACHESERVICECLASS Service)
 {
@@ -38,7 +39,7 @@ NTSTATUS CallCacheControl(UNICODE_STRING* PathName, BOOLEAN WithMapping, APPHELP
     {
         CacheEntry.ImageHandle = INVALID_HANDLE_VALUE;
     }
-    Status = NtApphelpCacheControl(Service, &CacheEntry);
+    Status = pNtApphelpCacheControl(Service, &CacheEntry);
     if (CacheEntry.ImageHandle != INVALID_HANDLE_VALUE)
         NtClose(CacheEntry.ImageHandle);
     return Status;
@@ -64,31 +65,31 @@ void CheckValidation(UNICODE_STRING* PathName)
     NTSTATUS Status;
 
     /* Validate the handling of a NULL pointer */
-    Status = NtApphelpCacheControl(ApphelpCacheServiceRemove, NULL);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceRemove, NULL);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, NULL);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, NULL);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
 
     /* Validate the handling of a NULL pointer inside the struct */
-    Status = NtApphelpCacheControl(ApphelpCacheServiceRemove, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceRemove, &CacheEntry);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
 
     /* Just call the dump function */
-    Status = NtApphelpCacheControl(ApphelpCacheServiceDump, NULL);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceDump, NULL);
     ok_ntstatus(Status, STATUS_SUCCESS);
 
     /* Validate the handling of an invalid handle inside the struct */
     CacheEntry.ImageName = *PathName;
     CacheEntry.ImageHandle = (HANDLE)2;
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
     ok_ntstatus(Status, STATUS_NOT_FOUND);
 
     /* Validate the handling of an invalid service number */
-    Status = NtApphelpCacheControl(999, NULL);
+    Status = pNtApphelpCacheControl(999, NULL);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
-    Status = NtApphelpCacheControl(999, &CacheEntry);
+    Status = pNtApphelpCacheControl(999, &CacheEntry);
     ok_ntstatus(Status, STATUS_INVALID_PARAMETER);
 }
 
@@ -154,7 +155,7 @@ static void RunApphelpCacheControlTests(SC_HANDLE service_handle)
         let's test invalid handle behavior */
     CacheEntry.ImageName = ntPath;
     CacheEntry.ImageHandle = 0;
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
     ok_ntstatus(Status, STATUS_NOT_FOUND);
 
     /* re-add it for the next test */
@@ -162,7 +163,7 @@ static void RunApphelpCacheControlTests(SC_HANDLE service_handle)
     Status = CallCacheControl(&ntPath, TRUE, ApphelpCacheServiceLookup);
     ok_ntstatus(Status, STATUS_SUCCESS);
     CacheEntry.ImageHandle = (HANDLE)1;
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
     ok_ntstatus(Status, STATUS_NOT_FOUND);
 
     /* and again */
@@ -170,7 +171,7 @@ static void RunApphelpCacheControlTests(SC_HANDLE service_handle)
     Status = CallCacheControl(&ntPath, TRUE, ApphelpCacheServiceLookup);
     ok_ntstatus(Status, STATUS_SUCCESS);
     CacheEntry.ImageHandle = (HANDLE)0x80000000;
-    Status = NtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
+    Status = pNtApphelpCacheControl(ApphelpCacheServiceLookup, &CacheEntry);
     ok_ntstatus(Status, STATUS_NOT_FOUND);
 
     RtlFreeHeap(RtlGetProcessHeap(), 0, ntPath.Buffer);
@@ -343,6 +344,14 @@ START_TEST(NtApphelpCacheControl)
         win_skip("RegisterServiceCtrlHandlerExA not available, skipping tests\n");
         return;
     }
+
+    pNtApphelpCacheControl = (void*)GetProcAddress(GetModuleHandleA("ntdll.dll"), "NtApphelpCacheControl");
+    if (!pNtApphelpCacheControl)
+    {
+        win_skip("NtApphelpCacheControl not available, skipping tests\n");
+        return;
+    }
+
     argc = winetest_get_mainargs(&argv);
     if(argc < 3)
     {
diff --git a/modules/rostests/apitests/ntdll/NtLoadUnloadKey.c b/modules/rostests/apitests/ntdll/NtLoadUnloadKey.c
index bc4f4b967aa..f9bb9c2937e 100644
--- a/modules/rostests/apitests/ntdll/NtLoadUnloadKey.c
+++ b/modules/rostests/apitests/ntdll/NtLoadUnloadKey.c
@@ -25,6 +25,7 @@
 
 #endif
 
+static NTSTATUS (NTAPI *pNtUnloadKey2)(POBJECT_ATTRIBUTES, ULONG);
 
 static BOOLEAN
 RetrieveCurrentModuleNTDirectory(
@@ -381,8 +382,12 @@ DisconnectRegistry(
                                OBJ_CASE_INSENSITIVE,
                                RootKey,
                                NULL);
-    // return NtUnloadKey(&ObjectAttributes);
-    return NtUnloadKey2(&ObjectAttributes, Flags);
+    if (!pNtUnloadKey2)
+    {
+        win_skip("NtUnloadKey2 unavailable, using NtUnloadKey. Flags %lu\n", Flags);
+        return NtUnloadKey(&ObjectAttributes);
+    }
+    return pNtUnloadKey2(&ObjectAttributes, Flags);
 }
 
 
@@ -409,6 +414,8 @@ START_TEST(NtLoadUnloadKey)
     BOOLEAN PrivilegeSet[2] = {FALSE, FALSE};
     WCHAR PathBuffer[MAX_PATH];
 
+    pNtUnloadKey2 = (PVOID)GetProcAddress(GetModuleHandleW(L"ntdll.dll"), "NtUnloadKey2");
+
     /* Retrieve our current directory */
     RetrieveCurrentModuleNTDirectory(&NtTestPath);
 
diff --git a/modules/rostests/apitests/ntdll/RtlCopyMappedMemory.c b/modules/rostests/apitests/ntdll/RtlCopyMappedMemory.c
index d6c3149096e..b7150dfc5c5 100644
--- a/modules/rostests/apitests/ntdll/RtlCopyMappedMemory.c
+++ b/modules/rostests/apitests/ntdll/RtlCopyMappedMemory.c
@@ -7,25 +7,35 @@
 
 #include "precomp.h"
 
+static NTSTATUS (NTAPI *pRtlCopyMappedMemory)(PVOID, const VOID *, SIZE_T);
+
 START_TEST(RtlCopyMappedMemory)
 {
     NTSTATUS Status;
     UCHAR Buffer1[32];
     UCHAR Buffer2[32];
-    
-    StartSeh() RtlCopyMappedMemory(NULL, NULL, 1);      EndSeh(STATUS_ACCESS_VIOLATION);
-    StartSeh() RtlCopyMappedMemory(Buffer1, NULL, 1);   EndSeh(STATUS_ACCESS_VIOLATION);
-    StartSeh() RtlCopyMappedMemory(NULL, Buffer1, 1);   EndSeh(STATUS_ACCESS_VIOLATION);
-    
+
+    pRtlCopyMappedMemory = (PVOID)GetProcAddress(GetModuleHandleW(L"ntdll.dll"),
+                                                 "RtlCopyMappedMemory");
+    if (!pRtlCopyMappedMemory)
+    {
+        win_skip("RtlCopyMappedMemory (NT >= 5.2 API) not available\n");
+        return;
+    }
+
+    StartSeh() pRtlCopyMappedMemory(NULL, NULL, 1);     EndSeh(STATUS_ACCESS_VIOLATION);
+    StartSeh() pRtlCopyMappedMemory(Buffer1, NULL, 1);  EndSeh(STATUS_ACCESS_VIOLATION);
+    StartSeh() pRtlCopyMappedMemory(NULL, Buffer1, 1);  EndSeh(STATUS_ACCESS_VIOLATION);
+
     StartSeh()
-        Status = RtlCopyMappedMemory(NULL, NULL, 0);
+        Status = pRtlCopyMappedMemory(NULL, NULL, 0);
     EndSeh(STATUS_SUCCESS);
     ok(Status == STATUS_SUCCESS, "RtlCopyMappedMemory returned %lx\n", Status);
     
     RtlFillMemory(Buffer1, sizeof(Buffer1), 0x11);
     RtlFillMemory(Buffer2, sizeof(Buffer2), 0x22);
     StartSeh()
-        Status = RtlCopyMappedMemory(Buffer1, Buffer2, sizeof(Buffer1));
+        Status = pRtlCopyMappedMemory(Buffer1, Buffer2, sizeof(Buffer1));
     EndSeh(STATUS_SUCCESS);
     ok(Status == STATUS_SUCCESS, "RtlCopyMappedMemory returned %lx\n", Status);
     ok(RtlCompareMemory(Buffer1, Buffer2, sizeof(Buffer1)) == sizeof(Buffer1), "Data not copied\n");