diff --git a/dll/win32/advapi32/sec/lsa.c b/dll/win32/advapi32/sec/lsa.c
index f88cc664e66..4b137aaecb9 100644
--- a/dll/win32/advapi32/sec/lsa.c
+++ b/dll/win32/advapi32/sec/lsa.c
@@ -23,15 +23,17 @@ LsapIsLocalComputer(PLSA_UNICODE_STRING ServerName)
     DWORD dwSize = MAX_COMPUTERNAME_LENGTH + 1;
     BOOL Result;
     LPWSTR buf;
+    PCWSTR pSrvName;
 
     if (ServerName == NULL || ServerName->Length == 0 || ServerName->Buffer == NULL)
         return TRUE;
 
+    pSrvName = ServerName->Buffer;
     buf = HeapAlloc(GetProcessHeap(), 0, dwSize * sizeof(WCHAR));
     Result = GetComputerNameW(buf, &dwSize);
-    if (Result && (ServerName->Buffer[0] == '\\') && (ServerName->Buffer[1] == '\\'))
-        ServerName += 2;
-    Result = Result && !lstrcmpW(ServerName->Buffer, buf);
+    if (Result && (pSrvName[0] == L'\\') && (pSrvName[1] == L'\\'))
+        pSrvName += 2;
+    Result = Result && !lstrcmpW(pSrvName, buf);
     HeapFree(GetProcessHeap(), 0, buf);
 
     return Result;