diff --git a/winpr/libwinpr/pipe/pipe.c b/winpr/libwinpr/pipe/pipe.c
index f1f76cb2e..c4857a1fb 100644
--- a/winpr/libwinpr/pipe/pipe.c
+++ b/winpr/libwinpr/pipe/pipe.c
@@ -332,7 +332,12 @@ BOOL NamedPipeRead(PVOID Object, LPVOID lpBuffer, DWORD nNumberOfBytesToRead,
 		/* synchronous behavior */
 		lpOverlapped->Internal = 0;
 		lpOverlapped->InternalHigh = (ULONG_PTR)nNumberOfBytesToRead;
-		lpOverlapped->DUMMYUNIONNAME.Pointer = (PVOID)lpBuffer;
+#if defined(NONAMELESSUNION)
+		lpOverlapped->DUMMYUNIONNAME.Pointer
+#else
+		lpOverlapped->Pointer
+#endif
+		    = (PVOID)lpBuffer;
 		(void)SetEvent(lpOverlapped->hEvent);
 #endif
 	}
@@ -426,7 +431,12 @@ BOOL NamedPipeWrite(PVOID Object, LPCVOID lpBuffer, DWORD nNumberOfBytesToWrite,
 				PVOID pv;
 			} cnv;
 			cnv.cpv = lpBuffer;
-			lpOverlapped->DUMMYUNIONNAME.Pointer = cnv.pv;
+#if defined(NONAMELESSUNION)
+			lpOverlapped->DUMMYUNIONNAME.Pointer
+#else
+			lpOverlapped->Pointer
+#endif
+			    = cnv.pv;
 		}
 		(void)SetEvent(lpOverlapped->hEvent);
 #endif
@@ -782,7 +792,12 @@ BOOL ConnectNamedPipe(HANDLE hNamedPipe, LPOVERLAPPED lpOverlapped)
 		/* synchronous behavior */
 		lpOverlapped->Internal = 2;
 		lpOverlapped->InternalHigh = (ULONG_PTR)0;
-		lpOverlapped->DUMMYUNIONNAME.Pointer = (PVOID)NULL;
+#if defined(NONAMELESSUNION)
+		lpOverlapped->DUMMYUNIONNAME.Pointer
+#else
+		lpOverlapped->Pointer
+#endif
+		    = (PVOID)NULL;
 		(void)SetEvent(lpOverlapped->hEvent);
 	}
 
diff --git a/winpr/libwinpr/sysinfo/sysinfo.c b/winpr/libwinpr/sysinfo/sysinfo.c
index b918c504b..7f0d585fc 100644
--- a/winpr/libwinpr/sysinfo/sysinfo.c
+++ b/winpr/libwinpr/sysinfo/sysinfo.c
@@ -231,7 +231,11 @@ void GetSystemInfo(LPSYSTEM_INFO lpSystemInfo)
 	WINPR_ASSERT(lpSystemInfo);
 
 	*lpSystemInfo = empty;
+#if defined(NONAMELESSUNION)
 	lpSystemInfo->DUMMYUNIONNAME.DUMMYSTRUCTNAME.wProcessorArchitecture =
+#else
+	lpSystemInfo->wProcessorArchitecture =
+#endif
 	    GetProcessorArchitecture();
 	lpSystemInfo->dwPageSize = GetSystemPageSize();
 	lpSystemInfo->dwNumberOfProcessors = GetNumberOfProcessors();
diff --git a/winpr/libwinpr/sysinfo/test/TestGetNativeSystemInfo.c b/winpr/libwinpr/sysinfo/test/TestGetNativeSystemInfo.c
index 91440fe16..a2c955d76 100644
--- a/winpr/libwinpr/sysinfo/test/TestGetNativeSystemInfo.c
+++ b/winpr/libwinpr/sysinfo/test/TestGetNativeSystemInfo.c
@@ -11,10 +11,17 @@ int TestGetNativeSystemInfo(int argc, char* argv[])
 
 	GetNativeSystemInfo(&sysinfo);
 
+#if defined(NONAMELESSUNION)
+	const UINT16 wProcessorArchitecture =
+	    sysinfo.DUMMYUNIONNAME.DUMMYSTRUCTNAME.wProcessorArchitecture;
+	const UINT16 wReserved = sysinfo.DUMMYUNIONNAME.DUMMYSTRUCTNAME.wReserved;
+#else
+	const UINT16 wProcessorArchitecture = sysinfo.wProcessorArchitecture;
+	const UINT16 wReserved = sysinfo.wReserved;
+#endif
 	printf("SystemInfo:\n");
-	printf("\twProcessorArchitecture: %" PRIu16 "\n",
-	       sysinfo.DUMMYUNIONNAME.DUMMYSTRUCTNAME.wProcessorArchitecture);
-	printf("\twReserved: %" PRIu16 "\n", sysinfo.DUMMYUNIONNAME.DUMMYSTRUCTNAME.wReserved);
+	printf("\twProcessorArchitecture: %" PRIu16 "\n", wProcessorArchitecture);
+	printf("\twReserved: %" PRIu16 "\n", wReserved);
 	printf("\tdwPageSize: 0x%08" PRIX32 "\n", sysinfo.dwPageSize);
 	printf("\tlpMinimumApplicationAddress: %p\n", sysinfo.lpMinimumApplicationAddress);
 	printf("\tlpMaximumApplicationAddress: %p\n", sysinfo.lpMaximumApplicationAddress);
diff --git a/winpr/libwinpr/wtsapi/wtsapi_win32.c b/winpr/libwinpr/wtsapi/wtsapi_win32.c
index 835d8c8e0..41a8e132c 100644
--- a/winpr/libwinpr/wtsapi/wtsapi_win32.c
+++ b/winpr/libwinpr/wtsapi/wtsapi_win32.c
@@ -663,7 +663,7 @@ BOOL Win32_WTSVirtualChannelPurge_Internal(HANDLE hChannelHandle, ULONG IoContro
 		return FALSE;
 	}
 
-	const NTSTATUS ntstatus =
+	NTSTATUS ntstatus =
 	    NtDeviceIoControlFile(pChannel->hFile, 0, 0, 0, &ioStatusBlock, IoControlCode, 0, 0, 0, 0);
 
 	if (ntstatus == STATUS_PENDING)
@@ -671,7 +671,13 @@ BOOL Win32_WTSVirtualChannelPurge_Internal(HANDLE hChannelHandle, ULONG IoContro
 		ntstatus = NtWaitForSingleObject(pChannel->hFile, 0, 0);
 
 		if (ntstatus >= 0)
+		{
+#if defined(NONAMELESSUNION)
 			ntstatus = ioStatusBlock.DUMMYUNIONNAME.Status;
+#else
+			ntstatus = ioStatusBlock.Status;
+#endif
+		}
 	}
 
 	if (ntstatus == STATUS_BUFFER_OVERFLOW)