diff --git a/src/wayland-server.c b/src/wayland-server.c
index eb6a3c5b..dc9b5105 100644
--- a/src/wayland-server.c
+++ b/src/wayland-server.c
@@ -1060,11 +1060,9 @@ get_socket_lock(struct wl_socket *socket)
 	return fd_lock;
 }
 
-WL_EXPORT int
-wl_display_add_socket(struct wl_display *display, const char *name)
+static int
+wl_socket_init_for_display_name(struct wl_socket *s, const char *name)
 {
-	struct wl_socket *s;
-	socklen_t size;
 	int name_size;
 	const char *runtime_dir;
 
@@ -1078,6 +1076,29 @@ wl_display_add_socket(struct wl_display *display, const char *name)
 		return -1;
 	}
 
+	s->addr.sun_family = AF_LOCAL;
+	name_size = snprintf(s->addr.sun_path, sizeof s->addr.sun_path,
+			     "%s/%s", runtime_dir, name) + 1;
+
+	assert(name_size > 0);
+	if (name_size > (int)sizeof s->addr.sun_path) {
+		wl_log("error: socket path \"%s/%s\" plus null terminator"
+		       " exceeds 108 bytes\n", runtime_dir, name);
+		/* to prevent programs reporting
+		 * "failed to add socket: Success" */
+		errno = ENAMETOOLONG;
+		return -1;
+	};
+
+	return 0;
+}
+
+WL_EXPORT int
+wl_display_add_socket(struct wl_display *display, const char *name)
+{
+	struct wl_socket *s;
+	socklen_t size;
+
 	s = malloc(sizeof *s);
 	memset(s, 0, sizeof *s);
 	if (s == NULL)
@@ -1088,20 +1109,10 @@ wl_display_add_socket(struct wl_display *display, const char *name)
 	if (name == NULL)
 		name = "wayland-0";
 
-	s->addr.sun_family = AF_LOCAL;
-	name_size = snprintf(s->addr.sun_path, sizeof s->addr.sun_path,
-			     "%s/%s", runtime_dir, name) + 1;
-
-	assert(name_size > 0);
-	if (name_size > (int)sizeof s->addr.sun_path) {
-		wl_log("error: socket path \"%s/%s\" plus null terminator"
-		       " exceeds 108 bytes\n", runtime_dir, name);
+	if (wl_socket_init_for_display_name(s, name) < 0) {
 		wl_socket_destroy(s);
-		/* to prevent programs reporting
-		 * "failed to add socket: Success" */
-		errno = ENAMETOOLONG;
 		return -1;
-	};
+	}
 
 	s->fd_lock = get_socket_lock(s);
 	if (s->fd_lock < 0) {
@@ -1115,7 +1126,7 @@ wl_display_add_socket(struct wl_display *display, const char *name)
 		return -1;
 	}
 
-	size = offsetof (struct sockaddr_un, sun_path) + name_size;
+	size = offsetof (struct sockaddr_un, sun_path) + strlen(s->addr.sun_path);
 	if (bind(s->fd, (struct sockaddr *) &s->addr, size) < 0) {
 		wl_log("bind() failed with error: %m\n");
 		wl_socket_destroy(s);