diff --git a/crates/ailang-codegen/src/lib.rs b/crates/ailang-codegen/src/lib.rs
index 30f5958..b9ce52d 100644
--- a/crates/ailang-codegen/src/lib.rs
+++ b/crates/ailang-codegen/src/lib.rs
@@ -376,6 +376,20 @@ fn lower_workspace_inner(ws: &Workspace, alloc: AllocStrategy) -> Result<String>
             let key = imp.alias.clone().unwrap_or_else(|| imp.module.clone());
             import_map.insert(key, imp.module.clone());
         }
+        // Iter 23.2 (fourth lockstep site, after Pattern::Ctor 15a /
+        // Term::Ctor typecheck / lookup_ctor_by_type codegen): mirror
+        // the typechecker's implicit-prelude import injection
+        // (crates/ailang-check/src/lib.rs:1198 and :1300). User
+        // modules that call prelude-resident fns synthesised by Iter
+        // 22b.3 monomorphisation (e.g. `prelude.eq__Int` from a user
+        // calling `eq x y` on Ints) need the codegen-side import_map
+        // to resolve the `prelude.` prefix at the call site
+        // (`lower_call`'s prefix lookup).
+        if m.name != "prelude" {
+            import_map
+                .entry("prelude".to_string())
+                .or_insert_with(|| "prelude".to_string());
+        }
 
         let mut emitter = Emitter::new(
             m,