diff --git a/src/main/java/org/prebid/server/bidder/grid/GridBidder.java b/src/main/java/org/prebid/server/bidder/grid/GridBidder.java
index e17048049d7..7512593d145 100644
--- a/src/main/java/org/prebid/server/bidder/grid/GridBidder.java
+++ b/src/main/java/org/prebid/server/bidder/grid/GridBidder.java
@@ -2,8 +2,12 @@
 
 import com.iab.openrtb.request.Imp;
 import com.iab.openrtb.response.Bid;
+import org.apache.commons.lang3.StringUtils;
 import org.prebid.server.bidder.OpenrtbBidder;
 import org.prebid.server.bidder.grid.model.ExtImpGrid;
+import org.prebid.server.bidder.grid.model.GridExtImp;
+import org.prebid.server.bidder.grid.model.GridExtImpData;
+import org.prebid.server.bidder.grid.model.GridExtImpDataAdServer;
 import org.prebid.server.exception.PreBidException;
 import org.prebid.server.json.JacksonMapper;
 import org.prebid.server.proto.openrtb.ext.response.BidType;
@@ -21,6 +25,26 @@ protected Imp modifyImp(Imp imp, ExtImpGrid impExt) {
         if (impExt.getUid() == null || impExt.getUid() == 0) {
             throw new PreBidException("uid is empty");
         }
+
+        final GridExtImp gridExtImp;
+        try {
+            gridExtImp = mapper.mapper().convertValue(imp.getExt(), GridExtImp.class);
+        } catch (Exception e) {
+            throw new PreBidException(e.getMessage());
+        }
+
+        final GridExtImpData extImpData = gridExtImp != null ? gridExtImp.getData() : null;
+        final GridExtImpDataAdServer adServer = extImpData != null ? extImpData.getAdServer() : null;
+        final String adSlot = adServer != null ? adServer.getAdSlot() : null;
+        if (StringUtils.isNotEmpty(adSlot)) {
+
+            final GridExtImp modifiedGridExtImp = gridExtImp.toBuilder()
+                    .gpid(adSlot)
+                    .build();
+
+            return imp.toBuilder().ext(mapper.mapper().valueToTree(modifiedGridExtImp)).build();
+        }
+
         return imp;
     }
 
diff --git a/src/main/java/org/prebid/server/bidder/grid/model/GridExtImp.java b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImp.java
new file mode 100644
index 00000000000..72fe1667058
--- /dev/null
+++ b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImp.java
@@ -0,0 +1,19 @@
+package org.prebid.server.bidder.grid.model;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import lombok.Builder;
+import lombok.Value;
+import org.prebid.server.proto.openrtb.ext.request.ExtImpPrebid;
+
+@Builder(toBuilder = true)
+@Value
+public class GridExtImp {
+
+    ExtImpPrebid prebid;
+
+    JsonNode bidder;
+
+    GridExtImpData data;
+
+    String gpid;
+}
diff --git a/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpData.java b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpData.java
new file mode 100644
index 00000000000..43d4e35bb91
--- /dev/null
+++ b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpData.java
@@ -0,0 +1,16 @@
+package org.prebid.server.bidder.grid.model;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+@AllArgsConstructor(staticName = "of")
+@Value
+public class GridExtImpData {
+
+    @JsonProperty("pbadslot")
+    String pbAdSlot;
+
+    @JsonProperty("adserver")
+    GridExtImpDataAdServer adServer;
+}
diff --git a/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpDataAdServer.java b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpDataAdServer.java
new file mode 100644
index 00000000000..a84828ba1c5
--- /dev/null
+++ b/src/main/java/org/prebid/server/bidder/grid/model/GridExtImpDataAdServer.java
@@ -0,0 +1,15 @@
+package org.prebid.server.bidder.grid.model;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+@AllArgsConstructor(staticName = "of")
+@Value
+public class GridExtImpDataAdServer {
+
+    String name;
+
+    @JsonProperty("adslot")
+    String adSlot;
+}
diff --git a/src/test/java/org/prebid/server/bidder/grid/GridBidderTest.java b/src/test/java/org/prebid/server/bidder/grid/GridBidderTest.java
index b775ae42e36..cbfa1d50094 100644
--- a/src/test/java/org/prebid/server/bidder/grid/GridBidderTest.java
+++ b/src/test/java/org/prebid/server/bidder/grid/GridBidderTest.java
@@ -12,6 +12,9 @@
 import org.junit.Test;
 import org.prebid.server.VertxTest;
 import org.prebid.server.bidder.grid.model.ExtImpGrid;
+import org.prebid.server.bidder.grid.model.GridExtImp;
+import org.prebid.server.bidder.grid.model.GridExtImpData;
+import org.prebid.server.bidder.grid.model.GridExtImpDataAdServer;
 import org.prebid.server.bidder.model.BidderBid;
 import org.prebid.server.bidder.model.BidderError;
 import org.prebid.server.bidder.model.HttpCall;
@@ -231,6 +234,23 @@ public void makeBidsShouldReturnErrorIfImpIdsFromBidAndRequestWereNotMatchedAndI
                 .containsOnly(BidderError.badServerResponse("Failed to find impression for ID: 123"));
     }
 
+    @Test
+    public void modifyImpShouldChangeImpExt() {
+        // given
+        final GridExtImp gridExtImp = GridExtImp.builder()
+                .data(GridExtImpData.of(null, GridExtImpDataAdServer.of("name", "adslot")))
+                .build();
+
+        final Imp imp = Imp.builder().ext(mapper.valueToTree(gridExtImp)).build();
+
+        // when
+        final Imp modifiedImp = gridBidder.modifyImp(imp, ExtImpGrid.of(1));
+
+        // then
+        assertThat(mapper.convertValue(modifiedImp.getExt(), GridExtImp.class).getGpid())
+                .isEqualTo(gridExtImp.getData().getAdServer().getAdSlot());
+    }
+
     private static BidResponse givenBidResponse(UnaryOperator<BidResponse.BidResponseBuilder> bidResponseCustomizer,
                                                 UnaryOperator<Bid.BidBuilder> bidCustomizer) {
         return bidResponseCustomizer.apply(BidResponse.builder()
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/grid/test-auction-grid-request.json b/src/test/resources/org/prebid/server/it/openrtb2/grid/test-auction-grid-request.json
index 6ea2e260623..7f190baf03f 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/grid/test-auction-grid-request.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/grid/test-auction-grid-request.json
@@ -14,6 +14,12 @@
       "ext": {
         "grid": {
           "uid": 1
+        },
+        "data": {
+          "adserver": {
+            "name": "some_name",
+            "adslot": "some_slot"
+          }
         }
       }
     }
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/grid/test-grid-bid-request-1.json b/src/test/resources/org/prebid/server/it/openrtb2/grid/test-grid-bid-request-1.json
index c0c1a403cad..816d7a24b98 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/grid/test-grid-bid-request-1.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/grid/test-grid-bid-request-1.json
@@ -14,7 +14,14 @@
       "ext": {
         "bidder": {
           "uid": 1
-        }
+        },
+        "data": {
+          "adserver": {
+            "name": "some_name",
+            "adslot": "some_slot"
+          }
+        },
+        "gpid" : "some_slot"
       }
     }
   ],