diff --git a/GeolocationPlugin.php b/GeolocationPlugin.php
index 418fe84..4a1c7bb 100644
--- a/GeolocationPlugin.php
+++ b/GeolocationPlugin.php
@@ -73,6 +73,7 @@ public function hookUninstall()
         delete_option('geolocation_per_page');
         delete_option('geolocation_add_map_to_contribution_form');
         delete_option('geolocation_use_metric_distances');
+        delete_option('geolocation_api_key');
 
         // This is for older versions of Geolocation, which used to store a Google Map API key.
         delete_option('geolocation_gmaps_key');
@@ -126,6 +127,7 @@ public function hookConfig($args)
         set_option('geolocation_use_metric_distances', $_POST['geolocation_use_metric_distances']);
         set_option('geolocation_map_type', $_POST['map_type']);
         set_option('geolocation_auto_fit_browse', $_POST['auto_fit_browse']);
+        set_option('geolocation_api_key', $_POST['api_key']);
     }
 
     public function hookDefineAcl($args)
@@ -156,15 +158,23 @@ public function hookDefineRoutes($args)
 
     public function hookAdminHead($args)
     {
-        queue_css_file('geolocation-marker');
-        queue_js_url("//maps.google.com/maps/api/js");
-        queue_js_file('map');
+        $this->_head();
     }
 
     public function hookPublicHead($args)
     {
+        $this->_head();
+    }
+
+    private function _head()
+    {
+        $key = get_option('geolocation_api_key');
+        $mapsUrl = '//maps.googleapis.com/maps/api/js';
+        if ($key) {
+            $mapsUrl .= "?key=$key";
+        }
         queue_css_file('geolocation-marker');
-        queue_js_url("//maps.google.com/maps/api/js");
+        queue_js_url($mapsUrl);
         queue_js_file('map');
     }
 
diff --git a/config_form.php b/config_form.php
index 60aeec3..8a5d2a3 100644
--- a/config_form.php
+++ b/config_form.php
@@ -48,6 +48,15 @@
         ?>
     </div>
 </div>
+<div class="field">
+    <div class="two columns alpha">
+        <label for="api_key"><?php echo __('API Key'); ?></label>
+    </div>
+    <div class="inputs five columns omega">
+        <p class="explanation"><?php echo __('Google API key for this project.'); ?></p>
+        <?php echo $view->formText('api_key', get_option('geolocation_api_key')); ?>
+    </div>
+</div>
 </fieldset>
 
 <fieldset>