diff --git a/lib/errno.in.h b/lib/errno.in.h
index 8022c0a..7cfed57 100644
--- a/lib/errno.in.h
+++ b/lib/errno.in.h
@@ -228,6 +228,11 @@
 #  define GNULIB_defined_ECANCELED 1
 # endif
 
+# ifndef EILSEQ
+#  define EILSEQ 2013
+#  define GNULIB_defined_EILSEQ 1
+# endif
+
 
 #endif /* address@hidden@_ERRNO_H */
 #endif /* address@hidden@_ERRNO_H */
diff --git a/lib/strerror-override.c b/lib/strerror-override.c
index 4e2c32b..685d768 100644
--- a/lib/strerror-override.c
+++ b/lib/strerror-override.c
@@ -283,6 +283,11 @@ strerror_override (int errnum)
       return "Operation canceled";
 #endif
 
+#if GNULIB_defined_EILSEQ
+    case EILSEQ:
+      return "Illegal byte sequence";
+#endif
+
     default:
       return NULL;
     }