diff --git a/common/cli_readline.c b/common/cli_readline.c
index 47b8762..5c158d0 100644
--- a/common/cli_readline.c
+++ b/common/cli_readline.c
@@ -493,8 +493,10 @@
 		}
 #endif
 		default:
-			cread_add_char(ichar, insert, &num, &eol_num, buf,
-				       *len);
+			if (ichar >= ' ' && ichar <= '~') {
+				cread_add_char(ichar, insert, &num, &eol_num,
+					       buf, *len);
+			}
 			break;
 		}
 	}