diff --git a/bitbake/lib/toaster/toastergui/static/css/default.css b/bitbake/lib/toaster/toastergui/static/css/default.css
index 88fe864e44..ff24e8c1ab 100644
--- a/bitbake/lib/toaster/toastergui/static/css/default.css
+++ b/bitbake/lib/toaster/toastergui/static/css/default.css
@@ -182,6 +182,7 @@ dd.variable-list form { margin-top: 10px; }
 .scrolling.has-error { border-color: #a94442; }
 .help-block.text-danger { color: #a94442; }
 .tooltip-inner code { color: #fff; }
+.text-danger > code { color: #a94442; }
 dd.variable-list .glyphicon-question-sign { font-size: 14px; }
 dd.variable-list .glyphicon-edit { font-size: 16px; }
 dt .glyphicon-trash { margin-left: 5px; font-size: 16px; }
diff --git a/bitbake/lib/toaster/toastergui/templates/projectconf.html b/bitbake/lib/toaster/toastergui/templates/projectconf.html
index c3ed216194..fcf6df2bf8 100644
--- a/bitbake/lib/toaster/toastergui/templates/projectconf.html
+++ b/bitbake/lib/toaster/toastergui/templates/projectconf.html
@@ -251,16 +251,16 @@ function validate_new_variable() {
     }
   }
 
-  var bad_chars  = /[^a-zA-Z0-9\-_]/.test(variable);
+  var bad_chars  = /[^a-zA-Z0-9\-_/]/.test(variable);
   var has_spaces = (0 <= variable.indexOf(" "));
   var only_spaces = (0 < variable.length) && (0 == variable.trim().length);
 
   if (only_spaces) {
     error_msg = "A valid variable name cannot include spaces";
   } else if (bad_chars && has_spaces) {
-    error_msg = "A valid variable name can only include letters, numbers, underscores, dashes, and cannot include spaces";
+    error_msg = "A valid variable name can only include letters, numbers and the special characters <code> _ - /</code>. Variable names cannot include spaces";
   } else if (bad_chars) {
-    error_msg = "A valid variable name can only include letters, numbers, underscores, and dashes";
+    error_msg = "A valid variable name can only include letters, numbers and the special characters <code>_ - /</code>";
   }
 
   if ("" != error_msg) {