diff --git a/src/js/_enqueues/wp/theme.js b/src/js/_enqueues/wp/theme.js
index 2115037671..a7481053b4 100644
--- a/src/js/_enqueues/wp/theme.js
+++ b/src/js/_enqueues/wp/theme.js
@@ -28,14 +28,16 @@ themes.Model = Backbone.Model.extend({
 	initialize: function() {
 		var description;
 
-		// If the theme is already installed, set an attribute.
-		if ( _.indexOf( themes.data.installedThemes, this.get( 'slug' ) ) !== -1 ) {
-			this.set({ installed: true });
-		}
+		if ( this.get( 'slug' ) ) {
+			// If the theme is already installed, set an attribute.
+			if ( _.indexOf( themes.data.installedThemes, this.get( 'slug' ) ) !== -1 ) {
+				this.set({ installed: true });
+			}
 
-		// If the theme is active, set an attribute.
-		if ( themes.data.activeTheme === this.get( 'slug' ) ) {
-			this.set({ active: true });
+			// If the theme is active, set an attribute.
+			if ( themes.data.activeTheme === this.get( 'slug' ) ) {
+				this.set({ active: true });
+			}
 		}
 
 		// Set the attributes.