diff --git a/src/ShellCheck/Checks/Commands.hs b/src/ShellCheck/Checks/Commands.hs
index 4bae17e..67c3c48 100644
--- a/src/ShellCheck/Checks/Commands.hs
+++ b/src/ShellCheck/Checks/Commands.hs
@@ -481,9 +481,16 @@ prop_checkUnusedEchoEscapes2 = verifyNot checkUnusedEchoEscapes "echo -e 'foi\\n
 prop_checkUnusedEchoEscapes3 = verify checkUnusedEchoEscapes "echo \"n:\\t42\""
 prop_checkUnusedEchoEscapes4 = verifyNot checkUnusedEchoEscapes "echo lol"
 prop_checkUnusedEchoEscapes5 = verifyNot checkUnusedEchoEscapes "echo -n -e '\n'"
+prop_checkUnusedEchoEscapes6 = verify checkUnusedEchoEscapes "echo '\\506'"
+prop_checkUnusedEchoEscapes7 = verify checkUnusedEchoEscapes "echo '\\5a'"
+prop_checkUnusedEchoEscapes8 = verifyNot checkUnusedEchoEscapes "echo '\\8a'"
+prop_checkUnusedEchoEscapes9 = verifyNot checkUnusedEchoEscapes "echo '\\d5a'"
+prop_checkUnusedEchoEscapes10 = verify checkUnusedEchoEscapes "echo '\\x4a'"
+prop_checkUnusedEchoEscapes11 = verify checkUnusedEchoEscapes "echo '\\xat'"
+prop_checkUnusedEchoEscapes12 = verifyNot checkUnusedEchoEscapes "echo '\\xth'"
 checkUnusedEchoEscapes = CommandCheck (Basename "echo") f
   where
-    hasEscapes = mkRegex "\\\\[rnt]"
+    hasEscapes = mkRegex "\\\\([rntabefv\\']|[0-7]{1,3}|x([0-9]|[A-F]|[a-f]){1,2})"
     f cmd =
         whenShell [Sh, Bash, Ksh] $
             unless (cmd `hasFlag` "e") $