diff --git a/README.md b/README.md
index 79ccc13..c0bbe25 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,7 @@ Switch input modes with Ctrl + key:
 	T  English
 	V  Vietnamese (Telex)
 	E  Emoji
+	P  Toggle preedit/candidate popup window
 
 Type romanized input. Select candidates with 1-9 or arrow keys.
 Tab or Enter to commit.
diff --git a/strans.c b/strans.c
index 9a1392e..42c00f5 100644
--- a/strans.c
+++ b/strans.c
@@ -2,6 +2,7 @@
 #include "fn.h"
 
 static Im im;
+static int popup = 1;
 static void dictqmap(Im*);
 
 static void
@@ -45,6 +46,8 @@ show(void)
 	Drawcmd dc;
 	int i, first, n;
 
+	if(!popup)
+		return;
 	sclear(&dc.pre);
 	if(!mapget(im.l->map, &im.pre, &dc.pre))
 		dc.pre = im.pre;
@@ -256,6 +259,10 @@ keystroke(u32int ks, u32int mod, Str *com)
 		reset();
 		if(ks >= 'a' && ks <= 'z')
 			ks -= 'a' - 1;
+		if(ks == 0x10){
+			popup = !popup;
+			return 1;
+		}
 		if(setlang(ks))
 			return 1;
 		return 0;