diff --git a/gdk/broadway/broadway-server.c b/gdk/broadway/broadway-server.c
index a82b3e82df..b54ae55149 100644
--- a/gdk/broadway/broadway-server.c
+++ b/gdk/broadway/broadway-server.c
@@ -36,6 +36,10 @@
 #include <string.h>
 #endif
 
+#if !GLIB_CHECK_VERSION (2, 67, 3)
+# define g_memdup2(mem,size)    g_memdup((mem), (size))
+#endif
+
 typedef struct {
   int id;
   guint32 tag;
@@ -605,7 +609,7 @@ update_future_pointer_info (BroadwayServer *server, BroadwayInputPointerMsg *dat
 static void
 queue_input_message (BroadwayServer *server, BroadwayInputMsg *msg)
 {
-  server->input_messages = g_list_append (server->input_messages, g_memdup (msg, sizeof (BroadwayInputMsg)));
+  server->input_messages = g_list_append (server->input_messages, g_memdup2 (msg, sizeof (BroadwayInputMsg)));
 }
 
 static void
diff --git a/gdk/broadway/gdkbroadway-server.c b/gdk/broadway/gdkbroadway-server.c
index 1aeb1649e9..02b6f93183 100644
--- a/gdk/broadway/gdkbroadway-server.c
+++ b/gdk/broadway/gdkbroadway-server.c
@@ -13,6 +13,8 @@
 #include "gdkbroadway-server.h"
 
 #include "gdkprivate-broadway.h"
+#include "gdk-private.h"
+
 #include <gdk/gdktextureprivate.h>
 
 #include <glib.h>
@@ -233,7 +235,7 @@ static void
 parse_all_input (GdkBroadwayServer *server)
 {
   guint8 *p, *end;
-  guint32 size;
+  size_t size;
   BroadwayReply *reply;
 
   p = server->recv_buffer;
@@ -245,7 +247,7 @@ parse_all_input (GdkBroadwayServer *server)
       if (p + size > end)
         break;
 
-      reply = g_memdup (p, size);
+      reply = g_memdup2 (p, size);
       p += size;
 
       server->incoming = g_list_append (server->incoming, reply);
diff --git a/gdk/broadway/gdksurface-broadway.c b/gdk/broadway/gdksurface-broadway.c
index 0d90e270a6..36930072c4 100644
--- a/gdk/broadway/gdksurface-broadway.c
+++ b/gdk/broadway/gdksurface-broadway.c
@@ -41,6 +41,7 @@
 #include "gdksurfaceprivate.h"
 #include "gdktextureprivate.h"
 #include "gdktoplevelprivate.h"
+#include "gdk-private.h"
 
 #include <graphene.h>
 #include <stdlib.h>
@@ -1025,7 +1026,7 @@ _gdk_broadway_moveresize_handle_event (GdkDisplay *display,
                 *mv_resize->moveresize_pending_event = *event;
               else
                 mv_resize->moveresize_pending_event =
-                  g_memdup (event, sizeof (BroadwayInputMsg));
+                  g_memdup2 (event, sizeof (BroadwayInputMsg));
 
               break;
             }
@@ -1043,7 +1044,7 @@ _gdk_broadway_moveresize_handle_event (GdkDisplay *display,
             *mv_resize->moveresize_pending_event = *event;
           else
             mv_resize->moveresize_pending_event =
-              g_memdup (event, sizeof (BroadwayInputMsg));
+              g_memdup2 (event, sizeof (BroadwayInputMsg));
 
           break;
         }