diff --git a/ChangeLog b/ChangeLog
index e090f83a8..da44c2840 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2022-04-20  Jun-ichi Takimoto  <takimoto-j@kba.biglobe.ne.jp>
+
+	* 50080: Src/hist.c: add missing STOUC() in casemodify()
+
 2022-04-19  Bart Schaefer  <schaefer@zsh.org>
 
 	* unposted (cf. users/27656 (Tomasz Pala), users/27660):
diff --git a/Src/hist.c b/Src/hist.c
index f9440dba7..bff0abe61 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -2254,10 +2254,10 @@ casemodify(char *str, int how)
 	    int c;
 	    int mod = 0;
 	    if (*str == Meta) {
-		c = str[1] ^ 32;
+		c = STOUC(str[1] ^ 32);
 		str += 2;
 	    } else
-		c = *str++;
+		c = STOUC(*str++);
 	    switch (how) {
 	    case CASMOD_LOWER:
 		if (isupper(c)) {