diff --git a/packages/server/src/api/routes/tests/search.spec.ts b/packages/server/src/api/routes/tests/search.spec.ts
index ee372914d7..76ce4a0243 100644
--- a/packages/server/src/api/routes/tests/search.spec.ts
+++ b/packages/server/src/api/routes/tests/search.spec.ts
@@ -3553,6 +3553,31 @@ if (descriptions.length) {
                     limit: 1,
                   }).toContainExactly([row])
                 })
+
+                isInternal &&
+                  describe("search by _id for relations", () => {
+                    it("can filter by the related _id", async () => {
+                      await expectSearch({
+                        query: {
+                          equal: { "rel._id": row.rel[0]._id },
+                        },
+                      }).toContainExactly([row])
+
+                      await expectSearch({
+                        query: {
+                          equal: { "rel._id": row.rel[1]._id },
+                        },
+                      }).toContainExactly([row])
+                    })
+
+                    it("can filter by the related _id and find nothing", async () => {
+                      await expectSearch({
+                        query: {
+                          equal: { "rel._id": "rel_none" },
+                        },
+                      }).toFindNothing()
+                    })
+                  })
               })
 
             !isInternal &&
diff --git a/packages/server/src/sdk/app/rows/queryUtils.ts b/packages/server/src/sdk/app/rows/queryUtils.ts
index ddd32870be..8ab50ea1b7 100644
--- a/packages/server/src/sdk/app/rows/queryUtils.ts
+++ b/packages/server/src/sdk/app/rows/queryUtils.ts
@@ -7,6 +7,7 @@ import {
 } from "@budibase/types"
 import { cloneDeep } from "lodash/fp"
 import sdk from "../../../sdk"
+import { isInternal } from "../tables/utils"
 
 export const removeInvalidFilters = (
   filters: SearchFilters,
@@ -70,6 +71,10 @@ export const getQueryableFields = async (
     opts?: { noRelationships?: boolean }
   ): Promise<string[]> => {
     const result = []
+    if (isInternal({ table })) {
+      result.push("_id")
+    }
+
     for (const field of Object.keys(table.schema).filter(
       f => allowedFields.includes(f) && table.schema[f].visible !== false
     )) {
@@ -113,14 +118,13 @@ export const getQueryableFields = async (
     return result
   }
 
-  const result = [
-    "_id", // Querying by _id is always allowed, even if it's never part of the schema
-  ]
+  // Querying by _id is always allowed, even if it's never part of the schema
+  const result = ["_id"]
 
   if (fields == null) {
     fields = Object.keys(table.schema)
   }
   result.push(...(await extractTableFields(table, fields, [table._id!])))
 
-  return result
+  return Array.from(new Set(result))
 }
diff --git a/packages/server/src/sdk/app/rows/tests/queryUtils.spec.ts b/packages/server/src/sdk/app/rows/tests/queryUtils.spec.ts
index f399801f1e..26a8431446 100644
--- a/packages/server/src/sdk/app/rows/tests/queryUtils.spec.ts
+++ b/packages/server/src/sdk/app/rows/tests/queryUtils.spec.ts
@@ -250,6 +250,8 @@ describe("query utils", () => {
       expect(result).toEqual([
         "_id",
         "name",
+        "aux._id",
+        "auxTable._id",
         "aux.title",
         "auxTable.title",
         "aux.name",
@@ -284,7 +286,14 @@ describe("query utils", () => {
       const result = await config.doInContext(config.appId, () => {
         return getQueryableFields(table)
       })
-      expect(result).toEqual(["_id", "name", "aux.name", "auxTable.name"])
+      expect(result).toEqual([
+        "_id",
+        "name",
+        "aux._id",
+        "auxTable._id",
+        "aux.name",
+        "auxTable.name",
+      ])
     })
 
     it("excludes all relationship fields if hidden", async () => {
@@ -387,10 +396,14 @@ describe("query utils", () => {
             "_id",
             "name",
             // aux1 primitive props
+            "aux1._id",
+            "aux1Table._id",
             "aux1.name",
             "aux1Table.name",
 
             // aux2 primitive props
+            "aux2._id",
+            "aux2Table._id",
             "aux2.title",
             "aux2Table.title",
           ])
@@ -405,14 +418,18 @@ describe("query utils", () => {
             "name",
 
             // aux2_1 primitive props
+            "aux2_1._id",
+            "aux2Table._id",
             "aux2_1.title",
             "aux2Table.title",
 
             // aux2_2 primitive props
+            "aux2_2._id",
             "aux2_2.title",
-            "aux2Table.title",
 
             // table primitive props
+            "table._id",
+            "TestTable._id",
             "table.name",
             "TestTable.name",
           ])
@@ -427,14 +444,18 @@ describe("query utils", () => {
             "title",
 
             // aux1_1 primitive props
+            "aux1_1._id",
+            "aux1Table._id",
             "aux1_1.name",
             "aux1Table.name",
 
             // aux1_2 primitive props
+            "aux1_2._id",
             "aux1_2.name",
-            "aux1Table.name",
 
             // table primitive props
+            "table._id",
+            "TestTable._id",
             "table.name",
             "TestTable.name",
           ])
@@ -481,6 +502,8 @@ describe("query utils", () => {
             "name",
 
             // deep 1 aux primitive props
+            "aux._id",
+            "auxTable._id",
             "aux.title",
             "auxTable.title",
           ])
@@ -495,6 +518,8 @@ describe("query utils", () => {
             "title",
 
             // deep 1 dependency primitive props
+            "table._id",
+            "TestTable._id",
             "table.name",
             "TestTable.name",
           ])