diff --git a/.changeset/cuddly-badgers-sit.md b/.changeset/cuddly-badgers-sit.md
new file mode 100644
index 000000000..c9880a281
--- /dev/null
+++ b/.changeset/cuddly-badgers-sit.md
@@ -0,0 +1,6 @@
+---
+"@apollo/gateway": patch
+"@apollo/query-graphs": patch
+---
+
+Avoid type explosion for inline fragments where the type condition is an interface that implements the parent type.
diff --git a/gateway-js/src/__tests__/executeQueryPlan.test.ts b/gateway-js/src/__tests__/executeQueryPlan.test.ts
index 160f4cf0e..c9e585f2f 100644
--- a/gateway-js/src/__tests__/executeQueryPlan.test.ts
+++ b/gateway-js/src/__tests__/executeQueryPlan.test.ts
@@ -2300,22 +2300,14 @@ describe('executeQueryPlan', () => {
 
       queryPlan = buildPlan(operation, queryPlanner);
 
-      // TODO: we're actually type-exploding in this case because currently, as soon as we need to type-explode, we do
-      // so into all the runtime types, while here it could make sense to only type-explode into the direct sub-types=
-      // (the sub-interfaces). We should fix this (but it's only sub-optimal, not incorrect).
       expect(queryPlan).toMatchInlineSnapshot(`
         QueryPlan {
           Fetch(service: "S1") {
             {
               allValues {
                 __typename
-                ... on T1 {
-                  a
-                }
-                ... on T2 {
-                  a
-                }
-                ... on T4 {
+                ... on SubInterface1 {
+                  __typename
                   a
                 }
               }
diff --git a/query-graphs-js/src/querygraph.ts b/query-graphs-js/src/querygraph.ts
index 1d98286c1..d2f738d40 100644
--- a/query-graphs-js/src/querygraph.ts
+++ b/query-graphs-js/src/querygraph.ts
@@ -1611,12 +1611,6 @@ class GraphBuilderFromSchema extends GraphBuilder {
       for (let j = i; j < abstractTypesWithTheirRuntimeTypes.length; j++) {
         const t2 = abstractTypesWithTheirRuntimeTypes[j];
 
-        // We ignore the pair if both are interfaces and one implements the other. We'll already have appropriate
-        // edges if that's the case.
-        if (isInterfaceType(t1.type) && isInterfaceType(t2.type) && (t1.type.implementsInterface(t2.type) || t2.type.implementsInterface(t1.type))) {
-          continue;
-        }
-
         let addT1ToT2 = false;
         let addT2ToT1 = false;
         if (t1.type === t2.type) {