diff --git a/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusRecordCursor.java b/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusRecordCursor.java
index 6beb1827cebd..874142bd92b4 100644
--- a/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusRecordCursor.java
+++ b/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusRecordCursor.java
@@ -14,7 +14,6 @@
 package io.trino.plugin.prometheus;
 
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
 import com.google.common.io.ByteSource;
 import com.google.common.io.CountingInputStream;
 import io.airlift.slice.Slice;
@@ -119,7 +118,7 @@ private Object getFieldValue(int field)
         int columnIndex = fieldToColumnIndex[field];
         switch (columnIndex) {
             case 0:
-                return fields.getLabels();
+                return getBlockFromMap(columnHandles.get(columnIndex).getColumnType(), fields.getLabels());
             case 1:
                 return fields.getTimestamp();
             case 2:
@@ -186,7 +185,7 @@ private List<PrometheusStandardizedRow> prometheusResultsInStandardizedForm(List
     {
         return results.stream().map(result ->
                 result.getTimeSeriesValues().getValues().stream().map(prometheusTimeSeriesValue -> new PrometheusStandardizedRow(
-                        getBlockFromMap(columnHandles.get(0).getColumnType(), ImmutableMap.copyOf(result.getMetricHeader())),
+                        result.getMetricHeader(),
                         prometheusTimeSeriesValue.getTimestamp(),
                         Double.parseDouble(prometheusTimeSeriesValue.getValue())))
                         .collect(Collectors.toList()))
diff --git a/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusStandardizedRow.java b/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusStandardizedRow.java
index 0ad038807453..e74d950c8198 100644
--- a/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusStandardizedRow.java
+++ b/plugin/trino-prometheus/src/main/java/io/trino/plugin/prometheus/PrometheusStandardizedRow.java
@@ -13,26 +13,27 @@
  */
 package io.trino.plugin.prometheus;
 
-import io.trino.spi.block.Block;
+import com.google.common.collect.ImmutableMap;
 
 import java.time.Instant;
+import java.util.Map;
 
 import static java.util.Objects.requireNonNull;
 
 public class PrometheusStandardizedRow
 {
-    private final Block labels;
+    private final Map<String, String> labels;
     private final Instant timestamp;
     private final Double value;
 
-    public PrometheusStandardizedRow(Block labels, Instant timestamp, Double value)
+    public PrometheusStandardizedRow(Map<String, String> labels, Instant timestamp, Double value)
     {
-        this.labels = requireNonNull(labels, "labels is null");
+        this.labels = ImmutableMap.copyOf(requireNonNull(labels, "labels is null"));
         this.timestamp = requireNonNull(timestamp, "timestamp is null");
         this.value = requireNonNull(value, "value is null");
     }
 
-    public Block getLabels()
+    public Map<String, String> getLabels()
     {
         return labels;
     }
diff --git a/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusIntegration.java b/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusIntegration.java
index a2dd9254279d..57a853a41d72 100644
--- a/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusIntegration.java
+++ b/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusIntegration.java
@@ -56,6 +56,13 @@ public void testSelectTable()
                 .matches("SELECT MAP(ARRAY[VARCHAR 'instance', '__name__', 'job'], ARRAY[VARCHAR 'localhost:9090', 'up', 'prometheus'])");
     }
 
+    @Test
+    public void testAggregation()
+    {
+        assertQuerySucceeds("SELECT count(*) FROM default.up"); // Don't check value since the row number isn't deterministic
+        assertQuery("SELECT avg(value) FROM default.up", "VALUES ('1.0')");
+    }
+
     @Test
     public void testPushDown()
     {
diff --git a/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusRecordSet.java b/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusRecordSet.java
index 95ea11885ad9..7405ec17b4cf 100644
--- a/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusRecordSet.java
+++ b/plugin/trino-prometheus/src/test/java/io/trino/plugin/prometheus/TestPrometheusRecordSet.java
@@ -27,6 +27,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static io.trino.plugin.prometheus.MetadataUtil.METRIC_CODEC;
 import static io.trino.plugin.prometheus.MetadataUtil.varcharMapType;
 import static io.trino.plugin.prometheus.PrometheusClient.TIMESTAMP_COLUMN_TYPE;
@@ -62,7 +63,8 @@ public void testCursorSimple()
         List<PrometheusStandardizedRow> actual = new ArrayList<>();
         while (cursor.advanceNextPosition()) {
             actual.add(new PrometheusStandardizedRow(
-                    (Block) cursor.getObject(0),
+                    getMapFromBlock(varcharMapType, (Block) cursor.getObject(0)).entrySet().stream()
+                            .collect(toImmutableMap(entry -> (String) entry.getKey(), entry -> (String) entry.getValue())),
                     (Instant) cursor.getObject(1),
                     cursor.getDouble(2)));
             assertFalse(cursor.isNull(0));
@@ -70,14 +72,14 @@ public void testCursorSimple()
             assertFalse(cursor.isNull(2));
         }
         List<PrometheusStandardizedRow> expected = ImmutableList.<PrometheusStandardizedRow>builder()
-                .add(new PrometheusStandardizedRow(getBlockFromMap(varcharMapType,
-                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus")), ofEpochMilli(1565962969044L), 1.0))
-                .add(new PrometheusStandardizedRow(getBlockFromMap(varcharMapType,
-                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus")), ofEpochMilli(1565962984045L), 1.0))
-                .add(new PrometheusStandardizedRow(getBlockFromMap(varcharMapType,
-                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus")), ofEpochMilli(1565962999044L), 1.0))
-                .add(new PrometheusStandardizedRow(getBlockFromMap(varcharMapType,
-                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus")), ofEpochMilli(1565963014044L), 1.0))
+                .add(new PrometheusStandardizedRow(
+                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus"), ofEpochMilli(1565962969044L), 1.0))
+                .add(new PrometheusStandardizedRow(
+                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus"), ofEpochMilli(1565962984045L), 1.0))
+                .add(new PrometheusStandardizedRow(
+                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus"), ofEpochMilli(1565962999044L), 1.0))
+                .add(new PrometheusStandardizedRow(
+                        ImmutableMap.of("instance", "localhost:9090", "__name__", "up", "job", "prometheus"), ofEpochMilli(1565963014044L), 1.0))
                 .build();
 
         assertThat(actual).as("actual")
@@ -85,7 +87,7 @@ public void testCursorSimple()
         for (int i = 0; i < actual.size(); i++) {
             PrometheusStandardizedRow actualRow = actual.get(i);
             PrometheusStandardizedRow expectedRow = expected.get(i);
-            assertEquals(getMapFromBlock(varcharMapType, actualRow.getLabels()), getMapFromBlock(varcharMapType, expectedRow.getLabels()));
+            assertEquals(getMapFromBlock(varcharMapType, getBlockFromMap(varcharMapType, actualRow.getLabels())), getMapFromBlock(varcharMapType, getBlockFromMap(varcharMapType, expectedRow.getLabels())));
             assertEquals(actualRow.getTimestamp(), expectedRow.getTimestamp());
             assertEquals(actualRow.getValue(), expectedRow.getValue());
         }