diff --git a/cli/src/repl/eval.rs b/cli/src/repl/eval.rs
index 89fd30e74f..ef6dfec3a4 100644
--- a/cli/src/repl/eval.rs
+++ b/cli/src/repl/eval.rs
@@ -6,6 +6,7 @@ use roc_gen_llvm::{run_jit_function, run_jit_function_dynamic_type};
 use roc_module::ident::{Lowercase, TagName};
 use roc_module::operator::CalledVia;
 use roc_module::symbol::{Interns, ModuleId, Symbol};
+use roc_mono::ir::TopLevelFunctionLayout;
 use roc_mono::layout::{union_sorted_tags_help, Builtin, Layout, UnionLayout, UnionVariant};
 use roc_parse::ast::{AssignedField, Expr, StrLiteral};
 use roc_region::all::{Located, Region};
@@ -37,7 +38,7 @@ pub unsafe fn jit_to_ast<'a>(
     arena: &'a Bump,
     lib: Library,
     main_fn_name: &str,
-    layout: &Layout<'a>,
+    layout: TopLevelFunctionLayout<'a>,
     content: &Content,
     interns: &Interns,
     home: ModuleId,
@@ -53,11 +54,14 @@ pub unsafe fn jit_to_ast<'a>(
     };
 
     match layout {
-        Layout::FunctionPointer(&[], result) => {
+        TopLevelFunctionLayout {
+            arguments: [],
+            result,
+        } => {
             // this is a thunk
-            jit_to_ast_help(&env, lib, main_fn_name, result, content)
+            jit_to_ast_help(&env, lib, main_fn_name, &result, content)
         }
-        _ => jit_to_ast_help(&env, lib, main_fn_name, layout, content),
+        _ => Err(ToAstProblem::FunctionLayout),
     }
 }
 
diff --git a/cli/src/repl/gen.rs b/cli/src/repl/gen.rs
index 699d244908..797fdba999 100644
--- a/cli/src/repl/gen.rs
+++ b/cli/src/repl/gen.rs
@@ -226,7 +226,7 @@ pub fn gen_and_eval<'a>(
                 &arena,
                 lib,
                 main_fn_name,
-                &arena.alloc(main_fn_layout).full(),
+                main_fn_layout,
                 &content,
                 &env.interns,
                 home,
diff --git a/compiler/gen_llvm/src/llvm/build.rs b/compiler/gen_llvm/src/llvm/build.rs
index d2beab5002..6b65b7d985 100644
--- a/compiler/gen_llvm/src/llvm/build.rs
+++ b/compiler/gen_llvm/src/llvm/build.rs
@@ -118,7 +118,7 @@ impl<'ctx> Iterator for FunctionIterator<'ctx> {
 #[derive(Default, Debug, Clone, PartialEq)]
 pub struct Scope<'a, 'ctx> {
     symbols: ImMap<Symbol, (Layout<'a>, BasicValueEnum<'ctx>)>,
-    pub top_level_thunks: ImMap<Symbol, (Layout<'a>, FunctionValue<'ctx>)>,
+    pub top_level_thunks: ImMap<Symbol, (TopLevelFunctionLayout<'a>, FunctionValue<'ctx>)>,
     join_points: ImMap<JoinPointId, (BasicBlock<'ctx>, &'a [PointerValue<'ctx>])>,
 }
 
@@ -136,7 +136,7 @@ impl<'a, 'ctx> Scope<'a, 'ctx> {
         function_value: FunctionValue<'ctx>,
     ) {
         self.top_level_thunks
-            .insert(symbol, (layout.full(), function_value));
+            .insert(symbol, (*layout, function_value));
     }
     fn remove(&mut self, symbol: &Symbol) {
         self.symbols.remove(symbol);
diff --git a/compiler/mono/src/ir.rs b/compiler/mono/src/ir.rs
index 3138184873..ff8a92d886 100644
--- a/compiler/mono/src/ir.rs
+++ b/compiler/mono/src/ir.rs
@@ -2624,10 +2624,6 @@ impl<'a> TopLevelFunctionLayout<'a> {
             },
         }
     }
-
-    pub fn full(&'a self) -> Layout<'a> {
-        Layout::FunctionPointer(self.arguments, &self.result)
-    }
 }
 
 fn specialize_naked_symbol<'a>(
@@ -6788,7 +6784,7 @@ fn call_specialized_proc<'a>(
                     arguments: field_symbols,
                 };
 
-                build_call(env, call, assigned, function_layout.full(), hole)
+                build_call(env, call, assigned, function_layout.result, hole)
             }
         }
     } else {