1 files changed, 3 insertions, 10 deletions
diff --git a/string.c b/string.c
index 4ab89a8e2f..4f9fe51f9f 100644
--- a/string.c
+++ b/string.c
@@ -8639,18 +8639,11 @@ str_compat_and_valid(VALUE str, rb_encoding *enc)
     if (cr == ENC_CODERANGE_BROKEN) {
 	rb_raise(rb_eArgError, "replacement must be valid byte sequence '%+"PRIsVALUE"'", str);
     }
-    else if (cr == ENC_CODERANGE_7BIT) {
-	rb_encoding *e = STR_ENC_GET(str);
-	if (!rb_enc_asciicompat(enc)) {
-	    rb_raise(rb_eEncCompatError, "incompatible character encodings: %s and %s",
-		    rb_enc_name(enc), rb_enc_name(e));
-	}
-    }
-    else { /* ENC_CODERANGE_VALID */
+    else {
 	rb_encoding *e = STR_ENC_GET(str);
-	if (enc != e) {
+	if (cr == ENC_CODERANGE_7BIT ? rb_enc_mbminlen(enc) != 1 : enc != e) {
 	    rb_raise(rb_eEncCompatError, "incompatible character encodings: %s and %s",
-		    rb_enc_name(enc), rb_enc_name(e));
+		     rb_enc_name(enc), rb_enc_name(e));
 	}
     }
     return str;