diff --git a/packages/relay-runtime/store/RelayReader.js b/packages/relay-runtime/store/RelayReader.js
index 9f314bc2e2916..fe5b16c39ac82 100644
--- a/packages/relay-runtime/store/RelayReader.js
+++ b/packages/relay-runtime/store/RelayReader.js
@@ -218,6 +218,9 @@ class RelayReader {
   }
 
   _markDataAsMissing(): void {
+    if (this._isWithinUnmatchedTypeRefinement) {
+      return;
+    }
     if (this._errorResponseFields == null) {
       this._errorResponseFields = [];
     }
diff --git a/packages/relay-runtime/store/__tests__/RelayReader-RelayErrorHandling-test.js b/packages/relay-runtime/store/__tests__/RelayReader-RelayErrorHandling-test.js
index afa5e5d4a6546..ad98487637efb 100644
--- a/packages/relay-runtime/store/__tests__/RelayReader-RelayErrorHandling-test.js
+++ b/packages/relay-runtime/store/__tests__/RelayReader-RelayErrorHandling-test.js
@@ -328,14 +328,61 @@ describe('RelayReader error fields', () => {
     );
 
     expect(isMissingData).toBe(false);
+    expect(errorResponseFields).toEqual(null);
+  });
 
-    // FIXME: This should be null
+  it('does report missing data within an inline fragment that does match', () => {
+    const source = RelayRecordSource.create({
+      'client:root': {
+        __id: 'client:root',
+        __typename: '__Root',
+        'node(id:"4")': {__ref: '4'},
+      },
+      'client:__type:User': {
+        __isMaybeNodeInterface: true,
+      },
+      '4': {
+        __id: '4',
+        id: '4',
+        __typename: 'NonNodeNoID',
+        // NOTE: `name` is missing
+      },
+    });
+
+    const FooQuery = graphql`
+      query RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery
+      @throwOnFieldError {
+        node(id: "4") {
+          # GraphQL lets us spread this here as long as there is at least one
+          # type that overlaps
+          ... on MaybeNodeInterface {
+            name
+          }
+        }
+      }
+    `;
+    const operation = createOperationDescriptor(FooQuery, {});
+    const {errorResponseFields, isMissingData} = read(
+      source,
+      operation.fragment,
+    );
+
+    expect(isMissingData).toBe(true);
     expect(errorResponseFields).toEqual([
+      // We are missing the metadata bout the interface
+      {
+        fieldPath: '',
+        handled: false,
+        kind: 'missing_expected_data.throw',
+        owner: 'RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery',
+      },
+      // We don't know if we should traverse into the inline fragment, but we do
+      // anyway and find that the field is missing
       {
         fieldPath: '',
         handled: false,
         kind: 'missing_expected_data.throw',
-        owner: 'RelayReaderRelayErrorHandlingTestInlineFragmentQuery',
+        owner: 'RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery',
       },
     ]);
   });
diff --git a/packages/relay-runtime/store/__tests__/__generated__/RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery.graphql.js b/packages/relay-runtime/store/__tests__/__generated__/RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery.graphql.js
new file mode 100644
index 0000000000000..90cc1b8d90191
--- /dev/null
+++ b/packages/relay-runtime/store/__tests__/__generated__/RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery.graphql.js
@@ -0,0 +1,132 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @oncall relay
+ *
+ * @generated SignedSource<<ac84fe2fe44c8d19a9d454523bef2f1d>>
+ * @flow
+ * @lightSyntaxTransform
+ * @nogrep
+ */
+
+/* eslint-disable */
+
+'use strict';
+
+/*::
+import type { ConcreteRequest, Query } from 'relay-runtime';
+export type RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$variables = {||};
+export type RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$data = {|
+  +node: ?{|
+    +name?: ?string,
+  |},
+|};
+export type RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery = {|
+  response: RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$data,
+  variables: RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$variables,
+|};
+*/
+
+var node/*: ConcreteRequest*/ = (function(){
+var v0 = [
+  {
+    "kind": "Literal",
+    "name": "id",
+    "value": "4"
+  }
+],
+v1 = {
+  "kind": "InlineFragment",
+  "selections": [
+    {
+      "alias": null,
+      "args": null,
+      "kind": "ScalarField",
+      "name": "name",
+      "storageKey": null
+    }
+  ],
+  "type": "MaybeNodeInterface",
+  "abstractKey": "__isMaybeNodeInterface"
+};
+return {
+  "fragment": {
+    "argumentDefinitions": [],
+    "kind": "Fragment",
+    "metadata": {
+      "throwOnFieldError": true
+    },
+    "name": "RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery",
+    "selections": [
+      {
+        "alias": null,
+        "args": (v0/*: any*/),
+        "concreteType": null,
+        "kind": "LinkedField",
+        "name": "node",
+        "plural": false,
+        "selections": [
+          (v1/*: any*/)
+        ],
+        "storageKey": "node(id:\"4\")"
+      }
+    ],
+    "type": "Query",
+    "abstractKey": null
+  },
+  "kind": "Request",
+  "operation": {
+    "argumentDefinitions": [],
+    "kind": "Operation",
+    "name": "RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery",
+    "selections": [
+      {
+        "alias": null,
+        "args": (v0/*: any*/),
+        "concreteType": null,
+        "kind": "LinkedField",
+        "name": "node",
+        "plural": false,
+        "selections": [
+          {
+            "alias": null,
+            "args": null,
+            "kind": "ScalarField",
+            "name": "__typename",
+            "storageKey": null
+          },
+          (v1/*: any*/),
+          {
+            "alias": null,
+            "args": null,
+            "kind": "ScalarField",
+            "name": "id",
+            "storageKey": null
+          }
+        ],
+        "storageKey": "node(id:\"4\")"
+      }
+    ]
+  },
+  "params": {
+    "cacheID": "0f7c4db114ac13634196313c2e57f4e4",
+    "id": null,
+    "metadata": {},
+    "name": "RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery",
+    "operationKind": "query",
+    "text": "query RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery {\n  node(id: \"4\") {\n    __typename\n    ... on MaybeNodeInterface {\n      __isMaybeNodeInterface: __typename\n      name\n    }\n    id\n  }\n}\n"
+  }
+};
+})();
+
+if (__DEV__) {
+  (node/*: any*/).hash = "5a20c30977bc87aac1a6449bc034610e";
+}
+
+module.exports = ((node/*: any*/)/*: Query<
+  RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$variables,
+  RelayReaderRelayErrorHandlingTestInlineFragmentMatchesQuery$data,
+>*/);