diff --git a/apiclient.js b/apiclient.js
index 5c64655..690e246 100644
--- a/apiclient.js
+++ b/apiclient.js
@@ -275,7 +275,7 @@
 
                         if (request.dataType == 'json' || request.headers.accept == 'application/json') {
                             return response.json();
-                        } else if ((response.headers.get('Content-Type') || '').toLowerCase().indexOf('text/') == 0) {
+                        } else if (request.dataType == 'text' || (response.headers.get('Content-Type') || '').toLowerCase().indexOf('text/') == 0) {
                             return response.text();
                         } else {
                             return response;
@@ -400,7 +400,7 @@
 
                     if (request.dataType == 'json' || request.headers.accept == 'application/json') {
                         return response.json();
-                    } else if ((response.headers.get('Content-Type') || '').toLowerCase().indexOf('text/') == 0) {
+                    } else if (request.dataType == 'text' || (response.headers.get('Content-Type') || '').toLowerCase().indexOf('text/') == 0) {
                         return response.text();
                     } else {
                         return response;
@@ -1304,6 +1304,9 @@
             if (!path) {
                 throw new Error("null path");
             }
+            if (typeof (path) !== 'string') {
+                throw new Error('invalid path');
+            }
 
             options = options || {};
 
@@ -1347,7 +1350,8 @@
 
             return self.ajax({
                 type: "GET",
-                url: url
+                url: url,
+                dataType: 'text'
             });
         };