diff --git a/repos/dde_rump/src/server/rump_fs/node.h b/repos/dde_rump/src/server/rump_fs/node.h
index ca540a9ec..650a1d77d 100644
--- a/repos/dde_rump/src/server/rump_fs/node.h
+++ b/repos/dde_rump/src/server/rump_fs/node.h
@@ -23,6 +23,7 @@
 
 
 namespace File_system {
+	using namespace Genode;
 	class Node;
 }
 
diff --git a/repos/libports/src/server/ffat_fs/directory.h b/repos/libports/src/server/ffat_fs/directory.h
index f305e3b06..4d8a2c5d8 100644
--- a/repos/libports/src/server/ffat_fs/directory.h
+++ b/repos/libports/src/server/ffat_fs/directory.h
@@ -18,6 +18,8 @@ namespace Ffat { extern "C" {
 
 namespace File_system {
 
+	using namespace Genode;
+
 	class Directory : public Node
 	{
 		private:
diff --git a/repos/libports/src/server/fuse_fs/node.h b/repos/libports/src/server/fuse_fs/node.h
index 1fd8e5c4c..056d4e604 100644
--- a/repos/libports/src/server/fuse_fs/node.h
+++ b/repos/libports/src/server/fuse_fs/node.h
@@ -19,6 +19,8 @@
 
 namespace File_system {
 
+	using namespace Genode;
+
 	typedef Genode::Path<MAX_PATH_LEN> Absolute_path;
 
 	class Node : public Node_base, public List<Node>::Element
diff --git a/repos/os/include/file_system/listener.h b/repos/os/include/file_system/listener.h
index 2a0ef6146..0719a2c4c 100644
--- a/repos/os/include/file_system/listener.h
+++ b/repos/os/include/file_system/listener.h
@@ -27,7 +27,7 @@ namespace File_system {
 
 			Listener() : _marked_as_updated(false) { }
 
-			Listener(Signal_context_capability sigh)
+			Listener(Genode::Signal_context_capability sigh)
 			: _sigh(sigh), _marked_as_updated(false) { }
 
 			void notify()
@@ -35,7 +35,7 @@ namespace File_system {
 				Genode::Lock::Guard guard(_lock);
 
 				if (_marked_as_updated && _sigh.valid())
-					Signal_transmitter(_sigh).submit();
+					Genode::Signal_transmitter(_sigh).submit();
 
 				_marked_as_updated = false;
 			}
diff --git a/repos/os/include/file_system/node.h b/repos/os/include/file_system/node.h
index edb1a0211..b26aaee66 100644
--- a/repos/os/include/file_system/node.h
+++ b/repos/os/include/file_system/node.h
@@ -19,8 +19,8 @@ namespace File_system {
 	{
 		private:
 
-			Lock           _lock;
-			List<Listener> _listeners;
+			Genode::Lock           _lock;
+			Genode::List<Listener> _listeners;
 
 		public:
 
diff --git a/repos/os/include/file_system/node_handle_registry.h b/repos/os/include/file_system/node_handle_registry.h
index 76a7f52f2..c4e5ffb9e 100644
--- a/repos/os/include/file_system/node_handle_registry.h
+++ b/repos/os/include/file_system/node_handle_registry.h
@@ -43,7 +43,7 @@ namespace File_system {
 			/* maximum number of open nodes per session */
 			enum { MAX_NODE_HANDLES = 128U };
 
-			Lock mutable _lock;
+			Genode::Lock mutable _lock;
 
 			Node_base *_nodes[MAX_NODE_HANDLES];
 
@@ -60,7 +60,7 @@ namespace File_system {
 			 */
 			int _alloc(Node_base *node)
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				for (unsigned i = 0; i < MAX_NODE_HANDLES; i++)
 					if (!_nodes[i]) {
@@ -96,7 +96,7 @@ namespace File_system {
 			 */
 			void free(Node_handle handle)
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				if (!_in_range(handle.value))
 					return;
@@ -132,7 +132,7 @@ namespace File_system {
 			template <typename HANDLE_TYPE>
 			typename Node_type<HANDLE_TYPE>::Type *lookup(HANDLE_TYPE handle)
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				if (!_in_range(handle.value))
 					throw Invalid_handle();
@@ -155,7 +155,7 @@ namespace File_system {
 			template <typename HANDLE_TYPE>
 			typename Node_type<HANDLE_TYPE>::Type *lookup_and_lock(HANDLE_TYPE handle)
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				if (!_in_range(handle.value))
 					throw Invalid_handle();
@@ -171,7 +171,7 @@ namespace File_system {
 
 			bool refer_to_same_node(Node_handle h1, Node_handle h2) const
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				if (!_in_range(h1.value) || !_in_range(h2.value)) {
 					PDBG("refer_to_same_node -> Invalid_handle");
@@ -184,9 +184,9 @@ namespace File_system {
 			/**
 			 * Register signal handler to be notified of node changes
 			 */
-			void sigh(Node_handle handle, Signal_context_capability sigh)
+			void sigh(Node_handle handle, Genode::Signal_context_capability sigh)
 			{
-				Lock::Guard guard(_lock);
+				Genode::Lock::Guard guard(_lock);
 
 				if (!_in_range(handle.value))
 					throw Invalid_handle();
diff --git a/repos/os/include/file_system/util.h b/repos/os/include/file_system/util.h
index ffc879ab3..965dec6be 100644
--- a/repos/os/include/file_system/util.h
+++ b/repos/os/include/file_system/util.h
@@ -117,7 +117,8 @@ namespace File_system {
 
 			collect_acknowledgements(source);
 
-			size_t const curr_packet_size = min(remaining_count, max_packet_size);
+			size_t const curr_packet_size =
+				Genode::min(remaining_count, max_packet_size);
 
 			Packet_descriptor
 				packet(source.alloc_packet(curr_packet_size),
@@ -132,10 +133,11 @@ namespace File_system {
 			packet = source.get_acked_packet();
 			success = packet.succeeded();
 
-			size_t const read_num_bytes = min(packet.length(), curr_packet_size);
+			size_t const read_num_bytes =
+				Genode::min(packet.length(), curr_packet_size);
 
 			/* copy-out payload into destination buffer */
-			memcpy(dst, source.packet_content(packet), read_num_bytes);
+			Genode::memcpy(dst, source.packet_content(packet), read_num_bytes);
 
 			source.release_packet(packet);
 
@@ -173,7 +175,8 @@ namespace File_system {
 
 			collect_acknowledgements(source);
 
-			size_t const curr_packet_size = min(remaining_count, max_packet_size);
+			size_t const curr_packet_size =
+				Genode::min(remaining_count, max_packet_size);
 
 			Packet_descriptor
 				packet(source.alloc_packet(curr_packet_size),
@@ -183,7 +186,7 @@ namespace File_system {
 				       seek_offset);
 
 			/* copy-out source buffer into payload */
-			memcpy(source.packet_content(packet), src, curr_packet_size);
+			Genode::memcpy(source.packet_content(packet), src, curr_packet_size);
 
 			/* pass packet to server side */
 			source.submit_packet(packet);
diff --git a/repos/os/include/file_system_session/client.h b/repos/os/include/file_system_session/client.h
index 2ba41cc26..11f656614 100644
--- a/repos/os/include/file_system_session/client.h
+++ b/repos/os/include/file_system_session/client.h
@@ -21,7 +21,7 @@
 namespace File_system { class Session_client; }
 
 
-class File_system::Session_client : public Rpc_client<Session>
+class File_system::Session_client : public Genode::Rpc_client<Session>
 {
 	private:
 
@@ -36,8 +36,8 @@ class File_system::Session_client : public Rpc_client<Session>
 		 * \param tx_buffer_alloc  allocator used for managing the
 		 *                         transmission buffer
 		 */
-		Session_client(Session_capability  session,
-		               Range_allocator    &tx_buffer_alloc)
+		Session_client(Session_capability       session,
+		               Genode::Range_allocator &tx_buffer_alloc)
 		:
 			Rpc_client<Session>(session),
 			_tx(call<Rpc_tx_cap>(), &tx_buffer_alloc)
@@ -101,7 +101,7 @@ class File_system::Session_client : public Rpc_client<Session>
 			call<Rpc_move>(from_dir, from_name, to_dir, to_name);
 		}
 
-		void sigh(Node_handle node, Signal_context_capability sigh) override
+		void sigh(Node_handle node, Genode::Signal_context_capability sigh) override
 		{
 			call<Rpc_sigh>(node, sigh);
 		}
diff --git a/repos/os/include/file_system_session/connection.h b/repos/os/include/file_system_session/connection.h
index e4e5489a3..f6802cdc3 100644
--- a/repos/os/include/file_system_session/connection.h
+++ b/repos/os/include/file_system_session/connection.h
@@ -37,11 +37,11 @@ struct File_system::Connection : Genode::Connection<Session>, Session_client
 	 *                         transmission buffer
 	 * \param tx_buf_size      size of transmission buffer in bytes
 	 */
-	Connection(Range_allocator &tx_block_alloc,
-	           size_t           tx_buf_size = DEFAULT_TX_BUF_SIZE,
-	           char const      *label       = "",
-	           char const      *root        = "/",
-	           bool             writeable   = true)
+	Connection(Genode::Range_allocator &tx_block_alloc,
+	           size_t                   tx_buf_size = DEFAULT_TX_BUF_SIZE,
+	           char const              *label       = "",
+	           char const              *root        = "/",
+	           bool                     writeable   = true)
 	:
 		Genode::Connection<Session>(
 			session("ram_quota=%zd, "
diff --git a/repos/os/include/file_system_session/file_system_session.h b/repos/os/include/file_system_session/file_system_session.h
index 6ccbf9554..ea4d09b60 100644
--- a/repos/os/include/file_system_session/file_system_session.h
+++ b/repos/os/include/file_system_session/file_system_session.h
@@ -21,13 +21,13 @@
 
 namespace File_system {
 
-	using namespace Genode;
-
 	struct Node_handle;
 	struct File_handle;
 	struct Dir_handle;
 	struct Symlink_handle;
 
+	using Genode::size_t;
+
 	typedef Genode::uint64_t seek_off_t;
 	typedef Genode::uint64_t file_size_t;
 
@@ -40,8 +40,8 @@ namespace File_system {
 
 	enum { MAX_NAME_LEN = 256, MAX_PATH_LEN = 1024 };
 
-	typedef Rpc_in_buffer<MAX_NAME_LEN> Name;
-	typedef Rpc_in_buffer<MAX_PATH_LEN> Path;
+	typedef Genode::Rpc_in_buffer<MAX_NAME_LEN> Name;
+	typedef Genode::Rpc_in_buffer<MAX_PATH_LEN> Path;
 
 	struct Status;
 	struct Control;
@@ -112,7 +112,7 @@ class File_system::Packet_descriptor : public Genode::Packet_descriptor
 
 		Node_handle _handle;   /* node handle */
 		Opcode      _op;       /* requested operation */
-		seek_off_t  _position; /* seek offset in bytes */
+		seek_off_t  _position; /* file seek offset in bytes */
 		size_t      _length;   /* transaction length in bytes */
 		bool        _success;  /* indicates success of operation */
 
@@ -121,9 +121,10 @@ class File_system::Packet_descriptor : public Genode::Packet_descriptor
 		/**
 		 * Constructor
 		 */
-		Packet_descriptor(off_t offset = 0, size_t size = 0)
+		Packet_descriptor(Genode::off_t  buf_offset = 0,
+		                  Genode::size_t buf_size   = 0)
 		:
-			Genode::Packet_descriptor(offset, size), _handle(-1),
+			Genode::Packet_descriptor(buf_offset, buf_size), _handle(-1),
 			_op(READ), _position(0), _length(0), _success(false) { }
 
 		/**
@@ -194,9 +195,9 @@ struct File_system::Session : public Genode::Session
 {
 	enum { TX_QUEUE_SIZE = 16 };
 
-	typedef Packet_stream_policy<File_system::Packet_descriptor,
-	                             TX_QUEUE_SIZE, TX_QUEUE_SIZE,
-	                             char> Tx_policy;
+	typedef Genode::Packet_stream_policy<File_system::Packet_descriptor,
+	                                     TX_QUEUE_SIZE, TX_QUEUE_SIZE,
+	                                     char> Tx_policy;
 
 	typedef Packet_stream_tx::Channel<Tx_policy> Tx;
 
@@ -303,7 +304,7 @@ struct File_system::Session : public Genode::Session
 	/**
 	 * Register handler that should be notified on node changes
 	 */
-	virtual void sigh(Node_handle, Signal_context_capability sigh) = 0;
+	virtual void sigh(Node_handle, Genode::Signal_context_capability sigh) = 0;
 
 	/**
 	 * Synchronize file system
@@ -318,7 +319,7 @@ struct File_system::Session : public Genode::Session
 	 ** RPC interface **
 	 *******************/
 
-	GENODE_RPC(Rpc_tx_cap, Capability<Tx>, _tx_cap);
+	GENODE_RPC(Rpc_tx_cap, Genode::Capability<Tx>, _tx_cap);
 	GENODE_RPC_THROW(Rpc_file, File_handle, file,
 	                 GENODE_TYPE_LIST(Invalid_handle, Node_already_exists,
 	                                  Invalid_name, Lookup_failed,
@@ -354,7 +355,7 @@ struct File_system::Session : public Genode::Session
 	                 Dir_handle, Name const &, Dir_handle, Name const &);
 	GENODE_RPC_THROW(Rpc_sigh, void, sigh,
 	                 GENODE_TYPE_LIST(Invalid_handle),
-	                 Node_handle, Signal_context_capability);
+	                 Node_handle, Genode::Signal_context_capability);
 	GENODE_RPC(Rpc_sync, void, sync, Node_handle);
 
 	/*
@@ -362,20 +363,20 @@ struct File_system::Session : public Genode::Session
 	 * exceeds the maximum number of type-list elements supported by
 	 * 'Genode::Meta::Type_list<>'.
 	 */
-	typedef Meta::Type_tuple<Rpc_tx_cap,
-	        Meta::Type_tuple<Rpc_file,
-	        Meta::Type_tuple<Rpc_symlink,
-	        Meta::Type_tuple<Rpc_dir,
-	        Meta::Type_tuple<Rpc_node,
-	        Meta::Type_tuple<Rpc_close,
-	        Meta::Type_tuple<Rpc_status,
-	        Meta::Type_tuple<Rpc_control,
-	        Meta::Type_tuple<Rpc_unlink,
-	        Meta::Type_tuple<Rpc_truncate,
-	        Meta::Type_tuple<Rpc_move,
-	        Meta::Type_tuple<Rpc_sigh,
-	        Meta::Type_tuple<Rpc_sync,
-	                         Meta::Empty>
+	typedef Genode::Meta::Type_tuple<Rpc_tx_cap,
+	        Genode::Meta::Type_tuple<Rpc_file,
+	        Genode::Meta::Type_tuple<Rpc_symlink,
+	        Genode::Meta::Type_tuple<Rpc_dir,
+	        Genode::Meta::Type_tuple<Rpc_node,
+	        Genode::Meta::Type_tuple<Rpc_close,
+	        Genode::Meta::Type_tuple<Rpc_status,
+	        Genode::Meta::Type_tuple<Rpc_control,
+	        Genode::Meta::Type_tuple<Rpc_unlink,
+	        Genode::Meta::Type_tuple<Rpc_truncate,
+	        Genode::Meta::Type_tuple<Rpc_move,
+	        Genode::Meta::Type_tuple<Rpc_sigh,
+	        Genode::Meta::Type_tuple<Rpc_sync,
+	                         Genode::Meta::Empty>
 	        > > > > > > > > > > > > Rpc_functions;
 };
 
diff --git a/repos/os/include/file_system_session/rpc_object.h b/repos/os/include/file_system_session/rpc_object.h
index 723b3eb35..be827a573 100644
--- a/repos/os/include/file_system_session/rpc_object.h
+++ b/repos/os/include/file_system_session/rpc_object.h
@@ -35,7 +35,8 @@ class File_system::Session_rpc_object : public Genode::Rpc_object<Session, Sessi
 		 *               for the tx packet stream
 		 * \param ep     entry point used for packet-stream channel
 		 */
-		Session_rpc_object(Dataspace_capability tx_ds, Rpc_entrypoint &ep)
+		Session_rpc_object(Genode::Dataspace_capability  tx_ds,
+		                   Genode::Rpc_entrypoint       &ep)
 		: _tx(tx_ds, ep) { }
 
 		/**
@@ -44,7 +45,7 @@ class File_system::Session_rpc_object : public Genode::Rpc_object<Session, Sessi
 		 * This method is called by the client via an RPC call at session
 		 * construction time.
 		 */
-		Capability<Tx> _tx_cap() { return _tx.cap(); }
+		Genode::Capability<Tx> _tx_cap() { return _tx.cap(); }
 
 		Tx::Sink *tx_sink() { return _tx.sink(); }
 };
diff --git a/repos/os/include/ram_fs/chunk.h b/repos/os/include/ram_fs/chunk.h
index c15d40870..3e872de70 100644
--- a/repos/os/include/ram_fs/chunk.h
+++ b/repos/os/include/ram_fs/chunk.h
@@ -22,6 +22,8 @@
 
 namespace File_system {
 
+	using namespace Genode;
+
 	using Genode::Noncopyable;
 
 	class Chunk_base;
diff --git a/repos/os/include/ram_fs/node.h b/repos/os/include/ram_fs/node.h
index c90506990..d3f8c00e7 100644
--- a/repos/os/include/ram_fs/node.h
+++ b/repos/os/include/ram_fs/node.h
@@ -19,7 +19,10 @@
 #include <file_system/node.h>
 #include <util/list.h>
 
-namespace File_system { class Node; }
+namespace File_system {
+	using namespace Genode;
+	class Node;
+}
 
 
 class File_system::Node : public Node_base, public List<Node>::Element
diff --git a/repos/os/src/server/fs_rom/main.cc b/repos/os/src/server/fs_rom/main.cc
index 389ad3d8c..6ba4e7af3 100755
--- a/repos/os/src/server/fs_rom/main.cc
+++ b/repos/os/src/server/fs_rom/main.cc
@@ -24,6 +24,8 @@
 #include <os/path.h>
 
 
+using namespace Genode;
+
 /*****************
  ** ROM service **
  *****************/
diff --git a/repos/os/src/server/lx_fs/directory.h b/repos/os/src/server/lx_fs/directory.h
index 7aec837e7..e95c5ee73 100644
--- a/repos/os/src/server/lx_fs/directory.h
+++ b/repos/os/src/server/lx_fs/directory.h
@@ -20,6 +20,7 @@
 
 
 namespace File_system {
+	using namespace Genode;
 	class Directory;
 }
 
diff --git a/repos/os/src/server/lx_fs/node.h b/repos/os/src/server/lx_fs/node.h
index a79783c48..96133a884 100644
--- a/repos/os/src/server/lx_fs/node.h
+++ b/repos/os/src/server/lx_fs/node.h
@@ -36,7 +36,7 @@ namespace File_system {
 			/**
 			 * Assign name
 			 */
-			void name(char const *name) { strncpy(_name, name, sizeof(_name)); }
+			void name(char const *name) { Genode::strncpy(_name, name, sizeof(_name)); }
 
 			virtual size_t read(char *dst, size_t len, seek_off_t) = 0;
 			virtual size_t write(char const *src, size_t len, seek_off_t) = 0;
diff --git a/repos/os/src/server/tar_fs/directory.h b/repos/os/src/server/tar_fs/directory.h
index f2e27652e..d56072429 100644
--- a/repos/os/src/server/tar_fs/directory.h
+++ b/repos/os/src/server/tar_fs/directory.h
@@ -22,6 +22,8 @@
 
 namespace File_system {
 
+	using namespace Genode;
+
 	class Directory : public Node
 	{
 		public:
diff --git a/repos/os/src/server/tar_fs/record.h b/repos/os/src/server/tar_fs/record.h
index fc2105f19..ba3e86338 100644
--- a/repos/os/src/server/tar_fs/record.h
+++ b/repos/os/src/server/tar_fs/record.h
@@ -19,6 +19,8 @@
 
 namespace File_system {
 
+	using namespace Genode;
+
 	class Record
 	{
 		private:
diff --git a/repos/os/src/server/trace_fs/node.h b/repos/os/src/server/trace_fs/node.h
index f405869dc..ea17dd2f2 100644
--- a/repos/os/src/server/trace_fs/node.h
+++ b/repos/os/src/server/trace_fs/node.h
@@ -15,6 +15,8 @@
 
 namespace File_system {
 
+	using namespace Genode;
+
 	class Node : public Node_base, public List<Node>::Element
 	{
 		public:
diff --git a/repos/os/src/server/vfs/node_cache.h b/repos/os/src/server/vfs/node_cache.h
index e0dca93a3..8b9b9ba9b 100644
--- a/repos/os/src/server/vfs/node_cache.h
+++ b/repos/os/src/server/vfs/node_cache.h
@@ -28,7 +28,7 @@ namespace File_system {
 	struct Symlink;
 	class Node_cache;
 
-	typedef Avl_string<MAX_PATH_LEN> Avl_path_string;
+	typedef Genode::Avl_string<MAX_PATH_LEN> Avl_path_string;
 
 	Vfs::File_system *root();
 }
@@ -38,7 +38,7 @@ namespace File_system {
  * Reference counted node object that can be inserted
  * into an AVL tree.
  */
-class File_system::Node : public Node_base, public Avl_node<Node>, private Noncopyable
+class File_system::Node : public Node_base, public Genode::Avl_node<Node>, private Genode::Noncopyable
 {
 	friend class Node_cache;
 
@@ -256,7 +256,7 @@ struct File_system::Symlink : Node
  * This structure deduplicates nodes between sessions, without it
  * the signal notifications would not propagate between sessions.
  */
-struct File_system::Node_cache : Avl_tree<Node>
+struct File_system::Node_cache : Genode::Avl_tree<Node>
 {
 	Node *find(char const *path) {
 		return first() ? (Node *)first()->find_by_path(path) : nullptr; }