diff --git a/index.js b/index.js
index 8c87d17..252872e 100644
--- a/index.js
+++ b/index.js
@@ -35,7 +35,7 @@ module.exports = {
     var mergeTrees = require('broccoli-merge-trees');
     var replace = require('broccoli-string-replace');
 
-    if (type === 'all' && process.env.EMBER_ENV === 'test') {
+    if (type === 'all' && process.env.EMBER_ENV === 'test' && process.env.NW_TEST) {
       // Update the base URL in `tests/index.html`
       var index = replace(tree, {
         files: ['tests/index.html'],
@@ -76,7 +76,7 @@ module.exports = {
   },
 
   contentFor: function(type) {
-    if (type === 'test-body' && process.env.EMBER_ENV === 'test') {
+    if (type === 'test-body' && process.env.EMBER_ENV === 'test' && process.env.NW_TEST) {
       var testemServer = process.env.NW_TESTEM_SERVER_URL;
       if (testemServer) {
         return '<script src="' + testemServer + '/socket.io/socket.io.js"></script>';
diff --git a/lib/commands/nw-test/index.js b/lib/commands/nw-test/index.js
index 14712f5..9ec1af1 100644
--- a/lib/commands/nw-test/index.js
+++ b/lib/commands/nw-test/index.js
@@ -110,6 +110,10 @@ module.exports = {
   },
 
   run: function(options) {
+    // Set environment variable to signal that this is the NW test command
+    // and not a regular test command
+    process.env.NW_TEST = true;
+
     options.outputPath = this.tmp();
 
     var promise;