1 files changed, 13 insertions, 1 deletions
diff --git a/unix/tkUnixEvent.c b/unix/tkUnixEvent.c
index 4d0ccfa..6268b25 100644
--- a/unix/tkUnixEvent.c
+++ b/unix/tkUnixEvent.c
@@ -116,8 +116,20 @@ TkpOpenDisplay(
     const char *displayNameStr)
 {
     TkDisplay *dispPtr;
-    Display *display = XOpenDisplay(displayNameStr);
+    Display *display;
+#ifdef TCL_THREADS
+    static int xinited = 0;
+
+    if (!xinited) {
+	/* Necessary for threaded apps, of no consequence otherwise  */
+	/* need only be called once, but must be called before *any* */
+	/* Xlib call is made.                                        */
+	XInitThreads();
+	xinited = 1;
+    }
+#endif
 
+    display = XOpenDisplay(displayNameStr);
     if (display == NULL) {
 	return NULL;
     }