diff --git a/BasiliskII/src/Unix/configure.ac b/BasiliskII/src/Unix/configure.ac
index afa459c0..9fa68ca2 100755
--- a/BasiliskII/src/Unix/configure.ac
+++ b/BasiliskII/src/Unix/configure.ac
@@ -881,6 +881,9 @@ if [[ "x$WANT_SDL_VIDEO" = "xyes" ]]; then
       EXTRASYSSRCS="$EXTRASYSSRCS ../dummy/clip_dummy.cpp"
       ;;
     esac
+    if [[ "$WANT_GTK" != "no" ]]; then
+      LIBS="$LIBS -lX11"
+    fi
   fi
 elif [[ "x$WANT_MACOSX_GUI" != "xyes" ]]; then
   VIDEOSRCS="video_x.cpp"
diff --git a/BasiliskII/src/Unix/main_unix.cpp b/BasiliskII/src/Unix/main_unix.cpp
old mode 100644
new mode 100755
index 48d05e22..4243744b
--- a/BasiliskII/src/Unix/main_unix.cpp
+++ b/BasiliskII/src/Unix/main_unix.cpp
@@ -63,6 +63,7 @@ struct sigstate {
 # ifdef HAVE_GNOMEUI
 #  include <gnome.h>
 # endif
+# include <X11/Xlib.h>
 #endif
 
 #ifdef ENABLE_XF86_DGA
@@ -384,6 +385,9 @@ static void usage(const char *prg_name)
 
 int main(int argc, char **argv)
 {
+#ifdef ENABLE_GTK
+	XInitThreads();
+#endif
 	const char *vmdir = NULL;
 	char str[256];