diff --git a/dlls/kernel/process.c b/dlls/kernel/process.c
index c44a3434b94..739fadb37ce 100644
--- a/dlls/kernel/process.c
+++ b/dlls/kernel/process.c
@@ -2468,16 +2468,28 @@ void WINAPI ExitProcess16( WORD status )
  */
 HANDLE WINAPI OpenProcess( DWORD access, BOOL inherit, DWORD id )
 {
-    HANDLE ret = 0;
-    SERVER_START_REQ( open_process )
+    NTSTATUS            status;
+    HANDLE              handle;
+    OBJECT_ATTRIBUTES   attr;
+    CLIENT_ID           cid;
+
+    cid.UniqueProcess = (HANDLE)id;
+    cid.UniqueThread = 0; /* FIXME ? */
+
+    attr.Length = sizeof(OBJECT_ATTRIBUTES);
+    attr.RootDirectory = NULL;
+    attr.Attributes = inherit ? OBJ_INHERIT : 0;
+    attr.SecurityDescriptor = NULL;
+    attr.SecurityQualityOfService = NULL;
+    attr.ObjectName = NULL;
+
+    status = NtOpenProcess(&handle, access, &attr, &cid);
+    if (status != STATUS_SUCCESS)
     {
-        req->pid     = id;
-        req->access  = access;
-        req->inherit = inherit;
-        if (!wine_server_call_err( req )) ret = reply->handle;
+        SetLastError( RtlNtStatusToDosError(status) );
+        return NULL;
     }
-    SERVER_END_REQ;
-    return ret;
+    return handle;
 }
 
 
diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index 0595042977b..c1e7f56de13 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -149,7 +149,7 @@
 @ stdcall NtOpenKey(ptr long ptr)
 @ stdcall NtOpenMutant(ptr long ptr)
 @ stub NtOpenObjectAuditAlarm
-@ stub NtOpenProcess
+@ stdcall NtOpenProcess(ptr long ptr ptr)
 @ stdcall NtOpenProcessToken(long long long)
 @ stdcall NtOpenSection(ptr long ptr)
 @ stdcall NtOpenSemaphore(long long ptr)
@@ -769,7 +769,7 @@
 @ stdcall ZwOpenKey(ptr long ptr) NtOpenKey
 @ stdcall ZwOpenMutant(ptr long ptr) NtOpenMutant
 @ stub ZwOpenObjectAuditAlarm
-@ stub ZwOpenProcess
+@ stdcall ZwOpenProcess(ptr long ptr ptr) NtOpenProcess
 @ stdcall ZwOpenProcessToken(long long long) NtOpenProcessToken
 @ stdcall ZwOpenSection(ptr long ptr) NtOpenSection
 @ stdcall ZwOpenSemaphore(long long ptr) NtOpenSemaphore
diff --git a/dlls/ntdll/process.c b/dlls/ntdll/process.c
index 4a4f6d84c26..fe05cf9b3f5 100644
--- a/dlls/ntdll/process.c
+++ b/dlls/ntdll/process.c
@@ -281,3 +281,24 @@ NTSTATUS WINAPI NtFlushInstructionCache(
 #endif
     return STATUS_SUCCESS;
 }
+
+/******************************************************************
+ *		NtOpenProcess [NTDLL.@]
+ *		ZwOpenProcess [NTDLL.@]
+ */
+NTSTATUS  WINAPI NtOpenProcess(PHANDLE handle, ACCESS_MASK access,
+                               const OBJECT_ATTRIBUTES* attr, const CLIENT_ID* cid)
+{
+    NTSTATUS    status;
+
+    SERVER_START_REQ( open_process )
+    {
+        req->pid     = (DWORD)cid->UniqueProcess;
+        req->access  = access;
+        req->inherit = attr && (attr->Attributes & OBJ_INHERIT);
+        status = wine_server_call( req );
+        if (!status) *handle = reply->handle;
+    }
+    SERVER_END_REQ;
+    return status;
+}
diff --git a/include/winternl.h b/include/winternl.h
index 36abdd6f28d..7d4e75d59c8 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -1695,6 +1695,7 @@ NTSTATUS  WINAPI NtOpenFile(PHANDLE,ACCESS_MASK,POBJECT_ATTRIBUTES,PIO_STATUS_BL
 NTSTATUS  WINAPI NtOpenIoCompletion(PHANDLE,ACCESS_MASK,POBJECT_ATTRIBUTES);
 NTSTATUS  WINAPI NtOpenKey(PHANDLE,ACCESS_MASK,const OBJECT_ATTRIBUTES *);
 NTSTATUS  WINAPI NtOpenMutant(PHANDLE,ACCESS_MASK,const OBJECT_ATTRIBUTES*);
+NTSTATUS  WINAPI NtOpenProcess(PHANDLE,ACCESS_MASK,const OBJECT_ATTRIBUTES*,const CLIENT_ID*);
 NTSTATUS  WINAPI NtOpenProcessToken(HANDLE,DWORD,HANDLE *);
 NTSTATUS  WINAPI NtOpenSection(HANDLE*,ACCESS_MASK,const OBJECT_ATTRIBUTES*);
 NTSTATUS  WINAPI NtOpenSemaphore(PHANDLE,ACCESS_MASK,const OBJECT_ATTRIBUTES*);