diff --git a/lib/core.js b/lib/core.js
index eb797ee1a..bd7ed512f 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -1195,10 +1195,33 @@
 
         function getSourcesParams(_sources, _sources_params, method_name) {
             for(var key in _sources) {
-                var pluginId = _sources[key];
-                var plugin = plugins[pluginId];
-                var params = plugin.methods[method_name];
-                _sources_params[key] = params.filter(param => param in result._debug.data);
+                var pluginIds = _sources[key];
+                if (!Array.isArray(pluginIds)) {
+                    pluginIds = [pluginIds];
+                }
+
+                var mergedParams = [];
+
+                for(var i = 0; i < pluginIds.length; i++) {
+                    var plugin = plugins[pluginIds[i]];
+                    var params = plugin.methods[method_name];
+
+                    if (!params && method_name === 'getVars' && CONFIG.GET_VARS_METHODS) {
+                        // Var may come from an aliased getVars method, e.g. `getContent` -> `content`.
+                        var aliasMethod = Object.keys(CONFIG.GET_VARS_METHODS).find(m => CONFIG.GET_VARS_METHODS[m] === key);
+                        if (aliasMethod) {
+                            params = plugin.methods[aliasMethod];
+                        }
+                    }
+
+                    if (params && params.filter) {
+                        mergedParams = mergedParams.concat(params.filter(param => param in result._debug.data));
+                    }
+                }
+
+                if (mergedParams.length) {
+                    _sources_params[key] = [...new Set(mergedParams)];
+                }
             }
         }