diff --git a/include/r_cvar.h b/include/r_cvar.h
index ee0a5b008..fd77424c5 100644
--- a/include/r_cvar.h
+++ b/include/r_cvar.h
@@ -21,6 +21,7 @@ extern struct cvar_s     *gl_dlight_polyblend;
 extern struct cvar_s     *gl_dlight_smooth;
 extern struct cvar_s     *gl_fb_bmodels;
 extern struct cvar_s     *gl_fb_models;
+extern struct cvar_s     *gl_finish;
 extern struct cvar_s     *gl_keeptjunctions;
 extern struct cvar_s     *gl_lerp_anim;
 extern struct cvar_s     *gl_driver;
diff --git a/libs/video/renderer/gl/gl_screen.c b/libs/video/renderer/gl/gl_screen.c
index 0d7d9f46e..2ce64bff6 100644
--- a/libs/video/renderer/gl/gl_screen.c
+++ b/libs/video/renderer/gl/gl_screen.c
@@ -271,4 +271,9 @@ SCR_UpdateScreen (double realtime, SCR_Func *scr_funcs)
 
 	GL_FlushText ();
 	qfglFlush ();
+
+	if (gl_finish->int_val) {
+		GL_EndRendering ();
+		begun = 0;
+	}
 }
diff --git a/libs/video/targets/vid_common_gl.c b/libs/video/targets/vid_common_gl.c
index 6be0abdec..2743356c9 100644
--- a/libs/video/targets/vid_common_gl.c
+++ b/libs/video/targets/vid_common_gl.c
@@ -114,6 +114,7 @@ int					gl_max_lights;
 
 cvar_t		*gl_doublebright;
 cvar_t      *gl_fb_bmodels;
+cvar_t      *gl_finish;
 cvar_t      *gl_max_size;
 cvar_t      *gl_multitexture;
 cvar_t		*gl_tessellate;
@@ -258,6 +259,8 @@ GL_Common_Init_Cvars (void)
 	gl_fb_bmodels = Cvar_Get ("gl_fb_bmodels", "1", CVAR_ARCHIVE,
 							  gl_fb_bmodels_f, "Toggles fullbright color "
 							  "support for bmodels");
+	gl_finish = Cvar_Get ("gl_finish", "1", CVAR_ARCHIVE, NULL,
+							"wait for rendering to finish");
 	gl_max_size = Cvar_Get ("gl_max_size", "0", CVAR_NONE, gl_max_size_f,
 							"Texture dimension");
 	gl_multitexture = Cvar_Get ("gl_multitexture", "0", CVAR_ARCHIVE,