diff --git a/packages/fireplace/lib/utils/expand_path.js b/packages/fireplace/lib/utils/expand_path.js
index <HASH>..<HASH> 100644
--- a/packages/fireplace/lib/utils/expand_path.js
+++ b/packages/fireplace/lib/utils/expand_path.js
@@ -4,7 +4,7 @@ FP.Utils = FP.Utils || {};
 FP.Utils.expandPath = function(path, opts) {
   return path.replace(/{{([^}]+)}}/g, function(match, optName){
     var value = get(opts, optName);
-    Ember.assert("missing part for path generation ("+optName+")", value);
+    Ember.assert("Missing part for path expansion, looking for "+optName+" in "+Ember.inspect(opts) + " for "+path, value);
     return value;
   });
 };
\ No newline at end of file
better assert message when path expansion is missing parts