diff --git a/dlls/kernel/sync.c b/dlls/kernel/sync.c
index 659ee3035c6..54f95a7a73d 100644
--- a/dlls/kernel/sync.c
+++ b/dlls/kernel/sync.c
@@ -807,6 +807,7 @@ HANDLE WINAPI CreateSemaphoreW( SECURITY_ATTRIBUTES *sa, LONG initial,
     {
         RtlInitUnicodeString( &nameW, name );
         attr.ObjectName = &nameW;
+        attr.RootDirectory = get_BaseNamedObjects_handle();
     }
 
     status = NtCreateSemaphore( &ret, SEMAPHORE_ALL_ACCESS, &attr, initial, max );
@@ -858,6 +859,7 @@ HANDLE WINAPI OpenSemaphoreW( DWORD access, BOOL inherit, LPCWSTR name )
     {
         RtlInitUnicodeString( &nameW, name );
         attr.ObjectName = &nameW;
+        attr.RootDirectory = get_BaseNamedObjects_handle();
     }
 
     status = NtOpenSemaphore( &ret, access, &attr );
diff --git a/dlls/ntdll/sync.c b/dlls/ntdll/sync.c
index f5d85aec1d2..675b9b71373 100644
--- a/dlls/ntdll/sync.c
+++ b/dlls/ntdll/sync.c
@@ -85,6 +85,7 @@ NTSTATUS WINAPI NtCreateSemaphore( OUT PHANDLE SemaphoreHandle,
     {
         req->access  = access;
         req->attributes = (attr) ? attr->Attributes : 0;
+        req->rootdir = attr ? attr->RootDirectory : 0;
         req->initial = InitialCount;
         req->max     = MaximumCount;
         if (len) wine_server_add_data( req, attr->ObjectName->Buffer, len );
@@ -111,6 +112,7 @@ NTSTATUS WINAPI NtOpenSemaphore( OUT PHANDLE SemaphoreHandle,
     {
         req->access  = access;
         req->attributes = (attr) ? attr->Attributes : 0;
+        req->rootdir = attr ? attr->RootDirectory : 0;
         if (len) wine_server_add_data( req, attr->ObjectName->Buffer, len );
         ret = wine_server_call( req );
         *SemaphoreHandle = reply->handle;
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index 18188467bce..c144f246523 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -707,6 +707,7 @@ struct create_semaphore_request
     struct request_header __header;
     unsigned int access;
     unsigned int attributes;
+    obj_handle_t rootdir;
     unsigned int initial;
     unsigned int max;
     /* VARARG(name,unicode_str); */
@@ -738,6 +739,7 @@ struct open_semaphore_request
     struct request_header __header;
     unsigned int access;
     unsigned int attributes;
+    obj_handle_t rootdir;
     /* VARARG(name,unicode_str); */
 };
 struct open_semaphore_reply
@@ -4306,6 +4308,6 @@ union generic_reply
     struct query_symlink_reply query_symlink_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 202
+#define SERVER_PROTOCOL_VERSION 203
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */
diff --git a/server/protocol.def b/server/protocol.def
index 934ae42c573..a691e90d53a 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -558,6 +558,7 @@ enum event_op { PULSE_EVENT, SET_EVENT, RESET_EVENT };
 @REQ(create_semaphore)
     unsigned int access;        /* wanted access rights */
     unsigned int attributes;    /* object attributes */
+    obj_handle_t rootdir;       /* root directory */
     unsigned int initial;       /* initial count */
     unsigned int max;           /* maximum count */
     VARARG(name,unicode_str);   /* object name */
@@ -579,6 +580,7 @@ enum event_op { PULSE_EVENT, SET_EVENT, RESET_EVENT };
 @REQ(open_semaphore)
     unsigned int access;        /* wanted access rights */
     unsigned int attributes;    /* object attributes */
+    obj_handle_t rootdir;       /* root directory */
     VARARG(name,unicode_str);   /* object name */
 @REPLY
     obj_handle_t handle;        /* handle to the semaphore */
diff --git a/server/semaphore.c b/server/semaphore.c
index bff60c5f528..e8d9cbbbba2 100644
--- a/server/semaphore.c
+++ b/server/semaphore.c
@@ -63,8 +63,8 @@ static const struct object_ops semaphore_ops =
 };
 
 
-static struct semaphore *create_semaphore( const struct unicode_str *name, unsigned int attr,
-                                           unsigned int initial, unsigned int max )
+static struct semaphore *create_semaphore( struct directory *root, const struct unicode_str *name,
+                                           unsigned int attr, unsigned int initial, unsigned int max )
 {
     struct semaphore *sem;
 
@@ -73,7 +73,7 @@ static struct semaphore *create_semaphore( const struct unicode_str *name, unsig
         set_error( STATUS_INVALID_PARAMETER );
         return NULL;
     }
-    if ((sem = create_named_object( sync_namespace, &semaphore_ops, name, attr )))
+    if ((sem = create_named_object_dir( root, name, attr, &semaphore_ops )))
     {
         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
         {
@@ -150,24 +150,36 @@ DECL_HANDLER(create_semaphore)
 {
     struct semaphore *sem;
     struct unicode_str name;
+    struct directory *root = NULL;
 
     reply->handle = 0;
     get_req_unicode_str( &name );
-    if ((sem = create_semaphore( &name, req->attributes, req->initial, req->max )))
+    if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
+        return;
+
+    if ((sem = create_semaphore( root, &name, req->attributes, req->initial, req->max )))
     {
         reply->handle = alloc_handle( current->process, sem, req->access,
                                       req->attributes & OBJ_INHERIT );
         release_object( sem );
     }
+
+    if (root) release_object( root );
 }
 
 /* open a handle to a semaphore */
 DECL_HANDLER(open_semaphore)
 {
     struct unicode_str name;
+    struct directory *root = NULL;
 
     get_req_unicode_str( &name );
-    reply->handle = open_object( sync_namespace, &name, &semaphore_ops, req->access, req->attributes );
+    if (req->rootdir && !(root = get_directory_obj( current->process, req->rootdir, 0 )))
+        return;
+
+    reply->handle = open_object_dir( root, &name, req->attributes, &semaphore_ops, req->access );
+
+    if (root) release_object( root );
 }
 
 /* release a semaphore */
diff --git a/server/trace.c b/server/trace.c
index 04c4bb40e39..e50e71ab2e8 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -968,6 +968,7 @@ static void dump_create_semaphore_request( const struct create_semaphore_request
 {
     fprintf( stderr, " access=%08x,", req->access );
     fprintf( stderr, " attributes=%08x,", req->attributes );
+    fprintf( stderr, " rootdir=%p,", req->rootdir );
     fprintf( stderr, " initial=%08x,", req->initial );
     fprintf( stderr, " max=%08x,", req->max );
     fprintf( stderr, " name=" );
@@ -994,6 +995,7 @@ static void dump_open_semaphore_request( const struct open_semaphore_request *re
 {
     fprintf( stderr, " access=%08x,", req->access );
     fprintf( stderr, " attributes=%08x,", req->attributes );
+    fprintf( stderr, " rootdir=%p,", req->rootdir );
     fprintf( stderr, " name=" );
     dump_varargs_unicode_str( cur_size );
 }