diff --git a/public/app/plugins/datasource/prometheus/completer.ts b/public/app/plugins/datasource/prometheus/completer.ts
index cb999581cdf..ebfb6670f40 100644
--- a/public/app/plugins/datasource/prometheus/completer.ts
+++ b/public/app/plugins/datasource/prometheus/completer.ts
@@ -113,7 +113,7 @@ export class PromCompleter {
         _.uniq(
           _.flatten(
             result.map(r => {
-              return Object.keys(r.metric);
+              return Object.keys(r);
             })
           )
         ),
@@ -151,7 +151,7 @@ export class PromCompleter {
       const labelValues = this.transformToCompletions(
         _.uniq(
           result.map(r => {
-            return r.metric[labelName];
+            return r[labelName];
           })
         ),
         'label value'
@@ -191,7 +191,7 @@ export class PromCompleter {
             _.uniq(
               _.flatten(
                 result.map(r => {
-                  return Object.keys(r.metric);
+                  return Object.keys(r);
                 })
               )
             ),
@@ -233,7 +233,7 @@ export class PromCompleter {
               _.uniq(
                 _.flatten(
                   result.map(r => {
-                    return Object.keys(r.metric);
+                    return Object.keys(r);
                   })
                 )
               ),
@@ -249,7 +249,7 @@ export class PromCompleter {
               _.uniq(
                 _.flatten(
                   result.map(r => {
-                    return Object.keys(r.metric);
+                    return Object.keys(r);
                   })
                 )
               ),
@@ -264,7 +264,7 @@ export class PromCompleter {
     return Promise.resolve([]);
   }
 
-  getLabelNameAndValueForExpression(expr, type) {
+  getLabelNameAndValueForExpression(expr: string, type: string): Promise<any> {
     if (this.labelQueryCache[expr]) {
       return Promise.resolve(this.labelQueryCache[expr]);
     }
@@ -276,9 +276,11 @@ export class PromCompleter {
       }
       query = '{__name__' + op + '"' + expr + '"}';
     }
-    return this.datasource.performInstantQuery({ expr: query }, new Date().getTime() / 1000).then(response => {
-      this.labelQueryCache[expr] = response.data.data.result;
-      return response.data.data.result;
+    const { start, end } = this.datasource.getTimeRange();
+    const url = '/api/v1/series?match[]=' + encodeURIComponent(query) + '&start=' + start + '&end=' + end;
+    return this.datasource.metadataRequest(url).then(response => {
+      this.labelQueryCache[expr] = response.data.data;
+      return response.data.data;
     });
   }
 
diff --git a/public/app/plugins/datasource/prometheus/datasource.ts b/public/app/plugins/datasource/prometheus/datasource.ts
index a07949490b2..9332a73caca 100644
--- a/public/app/plugins/datasource/prometheus/datasource.ts
+++ b/public/app/plugins/datasource/prometheus/datasource.ts
@@ -578,6 +578,14 @@ export class PrometheusDatasource {
     return Math.ceil(date.valueOf() / 1000);
   }
 
+  getTimeRange(): { start: number; end: number } {
+    let range = this.timeSrv.timeRange();
+    return {
+      start: this.getPrometheusTime(range.from, false),
+      end: this.getPrometheusTime(range.to, true),
+    };
+  }
+
   getOriginalMetricName(labelData) {
     return this.resultTransformer.getOriginalMetricName(labelData);
   }
diff --git a/public/app/plugins/datasource/prometheus/specs/completer.test.ts b/public/app/plugins/datasource/prometheus/specs/completer.test.ts
index 36765ef708b..7d2e7de8648 100644
--- a/public/app/plugins/datasource/prometheus/specs/completer.test.ts
+++ b/public/app/plugins/datasource/prometheus/specs/completer.test.ts
@@ -18,22 +18,12 @@ describe('Prometheus editor completer', () => {
   const backendSrv = {} as BackendSrv;
   const datasourceStub = new PrometheusDatasource({}, {}, backendSrv, {}, {});
 
-  datasourceStub.performInstantQuery = jest.fn(() =>
-    Promise.resolve({
-      data: {
-        data: {
-          result: [
-            {
-              metric: {
-                job: 'node',
-                instance: 'localhost:9100',
-              },
-            },
-          ],
-        },
-      },
-    })
+  datasourceStub.metadataRequest = jest.fn(() =>
+    Promise.resolve({ data: { data: [{ metric: { job: 'node', instance: 'localhost:9100' } }] } })
   );
+  datasourceStub.getTimeRange = jest.fn(() => {
+    return { start: 1514732400, end: 1514818800 };
+  });
   datasourceStub.performSuggestQuery = jest.fn(() => Promise.resolve(['node_cpu']));
 
   const templateSrv = {