diff --git a/Tests/ApolloCodegenTests/CodeGenIR/IRInputObjectTests.swift b/Tests/ApolloCodegenTests/CodeGenIR/IRInputObjectTests.swift
index 19c3123c0..e5b81d427 100644
--- a/Tests/ApolloCodegenTests/CodeGenIR/IRInputObjectTests.swift
+++ b/Tests/ApolloCodegenTests/CodeGenIR/IRInputObjectTests.swift
@@ -25,7 +25,7 @@ class IRInputObjectTests: XCTestCase {
 
   func buildSubject() async throws {
     let ir: IRBuilder = try await .mock(schema: schemaSDL, document: document)
-    subject = ir.schema.referencedTypes.inputObjects.first!
+    subject = ir.schema.referencedTypes.inputObjects[1]
   }
 
   // MARK: - Tests
diff --git a/apollo-ios-codegen/Sources/IR/IR+Schema.swift b/apollo-ios-codegen/Sources/IR/IR+Schema.swift
index 87d73e7c7..f459630ce 100644
--- a/apollo-ios-codegen/Sources/IR/IR+Schema.swift
+++ b/apollo-ios-codegen/Sources/IR/IR+Schema.swift
@@ -33,7 +33,8 @@ public final class Schema {
       _ types: [GraphQLNamedType],
       schemaRootTypes: CompilationResult.RootTypeDefinition
     ) {
-      self.allTypes = OrderedSet(types)
+      // Ensure allTypes is stable
+      self.allTypes = OrderedSet(types.sorted(by: { $0.name.schemaName < $1.name.schemaName }))
       self.schemaRootTypes = schemaRootTypes
 
       var objects = OrderedSet<GraphQLObjectType>()