diff --git a/devtools/client/shared/curl.js b/devtools/client/shared/curl.js
index 6d33ad971..967019746 100644
--- a/devtools/client/shared/curl.js
+++ b/devtools/client/shared/curl.js
@@ -375,6 +375,7 @@ const CurlUtils = {
                         .replace(/\'/g, "\\\'")
                         .replace(/\n/g, "\\n")
                         .replace(/\r/g, "\\r")
+                        .replace(/!/g, "\\041")
                         .replace(/[^\x20-\x7E]/g, escapeCharacter) + "'";
     }