diff --git a/README.md b/README.md
index c68633b..c834a94 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,8 @@ kana shown, and romaji that made no kana stays as typed until it is mended;
 The dictionary keys verbs and adjectives by stem and okurigana, so `kaku`
 offers かく's readings and then 書く and its kin — typing the okurigana
 with `Shift`, as SKK does, `kaKu`, asks for that split first. Katakana
-mode does not convert.
+mode does not convert, so there `Space` and `Tab` commit the reading and
+go on to the application.
 
 Korean composes one syllable at a time. `Enter`, `Tab`, `Esc` and any key
 that is not a jamo commit the syllable and go on to the application, so
diff --git a/strans.c b/strans.c
index f390ed9..6648f5f 100644
--- a/strans.c
+++ b/strans.c
@@ -871,12 +871,15 @@ transition(u32int ks, u32int mod, Str *com)
 	if((ks == ' ' || ks == Ktab) && isjp(&im) && haspre(&im) &&
 	   !(mod & ~Mshift)){
 		/* Space and Tab convert: they step through the candidates,
-		 * Katakana last; a reading with none is committed. */
+		 * Katakana last.  Katakana mode converts nothing, so there
+		 * the key only commits, and then it is the application's:
+		 * the space between two Katakana words is a space. */
 		katakouho();
-		if(im.nkouho != 0)
-			cyclekouho(mod & Mshift ? -1 : 1);
-		else
+		if(im.nkouho == 0){
 			flush(com);
+			return 0;
+		}
+		cyclekouho(mod & Mshift ? -1 : 1);
 		return 1;
 	}
 	if(ks == Ktab || ks == Kret || (ks == Kesc && !isjp(&im))){
diff --git a/tests/engine_test.c b/tests/engine_test.c
index ec635c2..3ac0e75 100644
--- a/tests/engine_test.c
+++ b/tests/engine_test.c
@@ -1441,6 +1441,16 @@ engine_katakana_sequences(struct ct *t)
 		checkstr(t, "committed Katakana", cases[i].want, &com);
 	}
 	CT_EQ_PTR(t, nil, getlang(LangJPK)->dictname);
+
+	/* Nothing to convert to: the key commits and goes on to the client. */
+	init();
+	im.l = getlang(LangJPK);
+	sclear(&com);
+	if(typekeys(t, "kaku", &com)){
+		CT_CHECK(t, !keystroke(' ', 0, &com));
+		checkstr(t, "Space commits the Katakana", "カク", &com);
+		CT_EQ_INT(t, 0, im.nkouho);
+	}
 }
 
 void