diff --git a/public/app/features/plugins/datasource_srv.ts b/public/app/features/plugins/datasource_srv.ts
index 32cc1b0deef..6483056f97b 100644
--- a/public/app/features/plugins/datasource_srv.ts
+++ b/public/app/features/plugins/datasource_srv.ts
@@ -244,11 +244,15 @@ export class DatasourceSrv implements DataSourceService {
 
     if (filters.variables) {
       for (const variable of this.templateSrv.getVariables()) {
-        if (variable.type !== 'datasource' || variable.multi || variable.includeAll) {
+        if (variable.type !== 'datasource') {
           continue;
         }
-        const dsName = variable.current.value === 'default' ? this.defaultName : variable.current.value;
-        const dsSettings = !Array.isArray(dsName) && this.settingsMapByName[dsName];
+        let dsValue = variable.current.value === 'default' ? this.defaultName : variable.current.value;
+        if (Array.isArray(dsValue) && dsValue.length === 1) {
+          // Support for multi-value variables with only one selected datasource
+          dsValue = dsValue[0];
+        }
+        const dsSettings = !Array.isArray(dsValue) && this.settingsMapByName[dsValue];
 
         if (dsSettings) {
           const key = `$\{${variable.name}\}`;
diff --git a/public/app/features/variables/guard.ts b/public/app/features/variables/guard.ts
index f6097fc5f35..524e959d061 100644
--- a/public/app/features/variables/guard.ts
+++ b/public/app/features/variables/guard.ts
@@ -25,7 +25,6 @@ import {
   VariableQueryEditorProps,
   VariableWithMultiSupport,
   VariableWithOptions,
-  DataSourceVariableModel,
 } from './types';
 
 /** @deprecated use a if (model.type === "query") type narrowing check instead */
@@ -43,10 +42,6 @@ export const isConstant = (model: VariableModel): model is ConstantVariableModel
   return model.type === 'constant';
 };
 
-export const isDataSource = (model: VariableModel): model is DataSourceVariableModel => {
-  return model.type === 'datasource';
-};
-
 export const isMulti = (model: VariableModel): model is VariableWithMultiSupport => {
   const withMulti = model as VariableWithMultiSupport;
   return withMulti.hasOwnProperty('multi') && typeof withMulti.multi === 'boolean';