diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
index aad9a9647f8..d143bcc96ef 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/aot.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
@@ -54,8 +54,8 @@ impl OngoingCodegen {
         self,
         sess: &Session,
         backend_config: &BackendConfig,
-    ) -> (CodegenResults, FxHashMap<WorkProductId, WorkProduct>) {
-        let mut work_products = FxHashMap::default();
+    ) -> (CodegenResults, FxIndexMap<WorkProductId, WorkProduct>) {
+        let mut work_products = FxIndexMap::default();
         let mut modules = vec![];
 
         for module_codegen in self.modules {
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index 9966cc2ef3c..095fbe62c19 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -88,7 +88,7 @@ mod prelude {
     };
     pub(crate) use rustc_target::abi::{Abi, FieldIdx, Scalar, Size, VariantIdx, FIRST_VARIANT};
 
-    pub(crate) use rustc_data_structures::fx::FxHashMap;
+    pub(crate) use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 
     pub(crate) use rustc_index::Idx;
 
@@ -223,7 +223,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
         ongoing_codegen: Box<dyn Any>,
         sess: &Session,
         _outputs: &OutputFilenames,
-    ) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
+    ) -> Result<(CodegenResults, FxIndexMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
         Ok(ongoing_codegen
             .downcast::<driver::aot::OngoingCodegen>()
             .unwrap()
diff --git a/compiler/rustc_codegen_gcc/src/lib.rs b/compiler/rustc_codegen_gcc/src/lib.rs
index 442ce0ea542..ea013c4428c 100644
--- a/compiler/rustc_codegen_gcc/src/lib.rs
+++ b/compiler/rustc_codegen_gcc/src/lib.rs
@@ -75,7 +75,7 @@ use rustc_codegen_ssa::back::write::{CodegenContext, FatLTOInput, ModuleConfig,
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
 use rustc_codegen_ssa::target_features::supported_target_features;
 use rustc_codegen_ssa::traits::{CodegenBackend, ExtraBackendMethods, ModuleBufferMethods, ThinBufferMethods, WriteBackendMethods};
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, Handler, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
 use rustc_metadata::EncodedMetadata;
@@ -137,7 +137,7 @@ impl CodegenBackend for GccCodegenBackend {
         Box::new(res)
     }
 
-    fn join_codegen(&self, ongoing_codegen: Box<dyn Any>, sess: &Session, _outputs: &OutputFilenames) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
+    fn join_codegen(&self, ongoing_codegen: Box<dyn Any>, sess: &Session, _outputs: &OutputFilenames) -> Result<(CodegenResults, FxIndexMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
         let (codegen_results, work_products) = ongoing_codegen
             .downcast::<rustc_codegen_ssa::back::write::OngoingCodegen<GccCodegenBackend>>()
             .expect("Expected GccCodegenBackend's OngoingCodegen, found Box<Any>")