Index: src/Makefile
==================================================================
--- src/Makefile
+++ src/Makefile
@@ -27,14 +27,14 @@
        XMPPRoster.m		\
        XMPPRosterItem.m		\
        XMPPSCRAMAuth.m		\
        XMPPStanza.m		\
        XMPPStreamManagement.m	\
-       XMPPXMLElementBuilder.m
+       XMPPXMLElementBuilder.m	\
+       namespaces.m
 
 INCLUDES = ${SRCS:.m=.h}	\
-	   namespaces.h		\
 	   ObjXMPP.h		\
 	   XMPPStorage.h
 
 include ../buildsys.mk
 

Index: src/XMPPConnection.m
==================================================================
--- src/XMPPConnection.m
+++ src/XMPPConnection.m
@@ -636,13 +636,17 @@
 		langString = [OFString stringWithFormat: @"xml:lang='%@' ",
 							 _language];
 
 	[_socket writeFormat: @"<?xml version='1.0'?>\n"
 			      @"<stream:stream to='%@' "
-			      @"xmlns='" XMPPClientNS @"' "
-			      @"xmlns:stream='" XMPPStreamNS @"' %@"
-			      @"version='1.0'>", _domain, langString];
+			      @"xmlns='%@' "
+			      @"xmlns:stream='%@' %@"
+			      @"version='1.0'>",
+			      _domain, 
+			      XMPPClientNS,
+			      XMPPStreamNS,
+			      langString];
 
 	_streamOpen = true;
 }
 
 - (void)close

Index: src/namespaces.h
==================================================================
--- src/namespaces.h
+++ src/namespaces.h
@@ -18,20 +18,22 @@
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define XMPPBindNS @"urn:ietf:params:xml:ns:xmpp-bind"
-#define XMPPCapsNS @"http://jabber.org/protocol/caps"
-#define XMPPClientNS @"jabber:client"
-#define XMPPDiscoInfoNS @"http://jabber.org/protocol/disco#info"
-#define XMPPDiscoItemsNS @"http://jabber.org/protocol/disco#items"
-#define XMPPMUCNS @"http://jabber.org/protocol/muc"
-#define XMPPRosterNS @"jabber:iq:roster"
-#define XMPPRosterVerNS @"urn:xmpp:features:rosterver"
-#define XMPPSASLNS @"urn:ietf:params:xml:ns:xmpp-sasl"
-#define XMPPSessionNS @"urn:ietf:params:xml:ns:xmpp-session"
-#define XMPPSMNS @"urn:xmpp:sm:3"
-#define XMPPStanzasNS @"urn:ietf:params:xml:ns:xmpp-stanzas"
-#define XMPPStartTLSNS @"urn:ietf:params:xml:ns:xmpp-tls"
-#define XMPPStreamNS @"http://etherx.jabber.org/streams"
-#define XMPPXMPPStreamNS @"urn:ietf:params:xml:ns:xmpp-streams"
+#import <ObjFW/ObjFW.h>
+
+extern OFString *const XMPPBindNS;
+extern OFString *const XMPPCapsNS;
+extern OFString *const XMPPClientNS;
+extern OFString *const XMPPDiscoInfoNS;
+extern OFString *const XMPPDiscoItemsNS;
+extern OFString *const XMPPMUCNS;
+extern OFString *const XMPPRosterNS;
+extern OFString *const XMPPRosterVerNS;
+extern OFString *const XMPPSASLNS;
+extern OFString *const XMPPSessionNS;
+extern OFString *const XMPPSMNS;
+extern OFString *const XMPPStanzasNS;
+extern OFString *const XMPPStartTLSNS;
+extern OFString *const XMPPStreamNS;
+extern OFString *const XMPPXMPPStreamNS;

ADDED   src/namespaces.m
Index: src/namespaces.m
==================================================================
--- /dev/null
+++ src/namespaces.m
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2011, 2021, Jonathan Schleifer <js@nil.im>
+ *
+ * https://heap.zone/objxmpp/
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "namespaces.h"
+
+OFString *const XMPPBindNS = @"urn:ietf:params:xml:ns:xmpp-bind";
+OFString *const XMPPCapsNS = @"http://jabber.org/protocol/caps";
+OFString *const XMPPClientNS = @"jabber:client";
+OFString *const XMPPDiscoInfoNS = @"http://jabber.org/protocol/disco#info";
+OFString *const XMPPDiscoItemsNS = @"http://jabber.org/protocol/disco#items";
+OFString *const XMPPMUCNS = @"http://jabber.org/protocol/muc";
+OFString *const XMPPRosterNS = @"jabber:iq:roster";
+OFString *const XMPPRosterVerNS = @"urn:xmpp:features:rosterver";
+OFString *const XMPPSASLNS = @"urn:ietf:params:xml:ns:xmpp-sasl";
+OFString *const XMPPSessionNS = @"urn:ietf:params:xml:ns:xmpp-session";
+OFString *const XMPPSMNS = @"urn:xmpp:sm:3";
+OFString *const XMPPStanzasNS = @"urn:ietf:params:xml:ns:xmpp-stanzas";
+OFString *const XMPPStartTLSNS = @"urn:ietf:params:xml:ns:xmpp-tls";
+OFString *const XMPPStreamNS = @"http://etherx.jabber.org/streams";
+OFString *const XMPPXMPPStreamNS = @"urn:ietf:params:xml:ns:xmpp-streams";