diff --git a/src/CHANGELOG b/src/CHANGELOG
index 1478aba70..239204353 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -200,7 +200,7 @@ ECL 8.9.0:
 
  - Hash tables were not properly serialized.
 
- - WRITE/READ-LINE did not work with gray streams (A. Vodonosov)
+ - WRITE/READ-LINE and READ-BYTE did not work with gray streams (A. Vodonosov)
 
  - When working with Gray streams, READ-LINE did not handle the EOF properly.
 
diff --git a/src/c/file.d b/src/c/file.d
index 28eab6207..a869998d7 100644
--- a/src/c/file.d
+++ b/src/c/file.d
@@ -994,7 +994,11 @@ ecl_read_byte(cl_object strm)
 BEGIN:
 #ifdef ECL_CLOS_STREAMS
 	if (ECL_INSTANCEP(strm)) {
-		return funcall(2, @'gray::stream-read-byte', strm);
+		cl_object b = funcall(2, @'gray::stream-read-byte', strm);
+		if (FIXNUMP(b) || type_of(b) == t_bignum) {
+			return b;
+		}
+		return Cnil;
 	}
 #endif
 	if (type_of(strm) != t_stream)