diff --git a/ext/iconv/tests/eucjp2iso2022jp.phpt b/ext/iconv/tests/eucjp2iso2022jp.phpt
index 6c1a8ec1214b..c3260c370f08 100644
--- a/ext/iconv/tests/eucjp2iso2022jp.phpt
+++ b/ext/iconv/tests/eucjp2iso2022jp.phpt
@@ -2,6 +2,16 @@
 EUC-JP to ISO-2022-JP
 --EXTENSIONS--
 iconv
+--SKIPIF--
+<?php
+// ISO-2022-JP is a stateful encoding, so the right answer is not
+// unique. In particular, musl (type "unknown") is known to have an
+// inefficient encoding for it that does not agree with the expected
+// output below.
+if (ICONV_IMPL == "unknown") {
+    die("skip byte-comparison of stateful encoding with unknown iconv");
+}
+?>
 --INI--
 error_reporting=2039
 --FILE--
diff --git a/ext/iconv/tests/iconv_mime_encode.phpt b/ext/iconv/tests/iconv_mime_encode.phpt
index e055f53b016a..c6f41c56ad90 100644
--- a/ext/iconv/tests/iconv_mime_encode.phpt
+++ b/ext/iconv/tests/iconv_mime_encode.phpt
@@ -2,6 +2,16 @@
 iconv_mime_encode()
 --EXTENSIONS--
 iconv
+--SKIPIF--
+<?php
+// ISO-2022-JP is a stateful encoding, so the right answer is not
+// unique. In particular, musl (type "unknown") is known to have an
+// inefficient encoding for it that does not agree with the expected
+// output below.
+if (ICONV_IMPL == "unknown") {
+    die("skip byte-comparison of stateful encoding with unknown iconv");
+}
+?>
 --INI--
 iconv.internal_charset=iso-8859-1
 --FILE--