diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c
index 855aa9cd1eb..24de360d983 100644
--- a/dlls/ntdll/unix/virtual.c
+++ b/dlls/ntdll/unix/virtual.c
@@ -6022,10 +6022,11 @@ NTSTATUS WINAPI NtFlushInstructionCache( HANDLE handle, const void *addr, SIZE_T
 /**********************************************************************
  *           NtFlushProcessWriteBuffers  (NTDLL.@)
  */
-void WINAPI NtFlushProcessWriteBuffers(void)
+NTSTATUS WINAPI NtFlushProcessWriteBuffers(void)
 {
     static int once = 0;
     if (!once++) FIXME( "stub\n" );
+    return STATUS_SUCCESS;
 }
 
 
diff --git a/dlls/wow64/process.c b/dlls/wow64/process.c
index 880b7623b10..c144af7743c 100644
--- a/dlls/wow64/process.c
+++ b/dlls/wow64/process.c
@@ -431,8 +431,7 @@ NTSTATUS WINAPI wow64_NtDebugActiveProcess( UINT *args )
  */
 NTSTATUS WINAPI wow64_NtFlushProcessWriteBuffers( UINT *args )
 {
-    NtFlushProcessWriteBuffers();
-    return STATUS_SUCCESS;
+    return NtFlushProcessWriteBuffers();
 }
 
 
diff --git a/include/winternl.h b/include/winternl.h
index 40d4ca4716a..aad7fe58105 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -4404,7 +4404,7 @@ NTSYSAPI NTSTATUS  WINAPI NtFindAtom(const WCHAR*,ULONG,RTL_ATOM*);
 NTSYSAPI NTSTATUS  WINAPI NtFlushBuffersFile(HANDLE,IO_STATUS_BLOCK*);
 NTSYSAPI NTSTATUS  WINAPI NtFlushInstructionCache(HANDLE,LPCVOID,SIZE_T);
 NTSYSAPI NTSTATUS  WINAPI NtFlushKey(HANDLE);
-NTSYSAPI void      WINAPI NtFlushProcessWriteBuffers(void);
+NTSYSAPI NTSTATUS  WINAPI NtFlushProcessWriteBuffers(void);
 NTSYSAPI NTSTATUS  WINAPI NtFlushVirtualMemory(HANDLE,LPCVOID*,SIZE_T*,ULONG);
 NTSYSAPI NTSTATUS  WINAPI NtFlushWriteBuffer(VOID);
 NTSYSAPI NTSTATUS  WINAPI NtFreeVirtualMemory(HANDLE,PVOID*,SIZE_T*,ULONG);