diff --git a/compiler/module/src/symbol.rs b/compiler/module/src/symbol.rs
index dea7b585d6..4ab921501f 100644
--- a/compiler/module/src/symbol.rs
+++ b/compiler/module/src/symbol.rs
@@ -575,6 +575,7 @@ define_builtins! {
         4 INT_MOD: "mod"
         5 INT_HIGHEST: "highest"
         6 INT_LOWEST: "lowest"
+        7 INT_ADD: "add"
     }
     3 FLOAT: "Float" => {
         0 FLOAT_FLOAT: "Float" imported // the Float.Float type alias
@@ -585,6 +586,7 @@ define_builtins! {
         5 FLOAT_SQRT: "sqrt"
         6 FLOAT_HIGHEST: "highest"
         7 FLOAT_LOWEST: "lowest"
+        8 FLOAT_ADD: "add"
     }
     4 BOOL: "Bool" => {
         0 BOOL_BOOL: "Bool" imported // the Bool.Bool type alias
diff --git a/compiler/mono/src/expr.rs b/compiler/mono/src/expr.rs
index d9b6c9a928..a45af92586 100644
--- a/compiler/mono/src/expr.rs
+++ b/compiler/mono/src/expr.rs
@@ -264,13 +264,23 @@ fn from_can<'a>(
         }
 
         Call(boxed, loc_args, _) => {
-            let (fn_var, loc_expr, _) = *boxed;
+            let (fn_var, loc_expr, ret_var) = *boxed;
+
+            let specialize_builtin_functions = {
+                |symbol, subs: &Subs| match dbg!(symbol) {
+                    Symbol::NUM_ADD => match to_int_or_float(subs, ret_var) {
+                        IntOrFloat::FloatType => Symbol::FLOAT_ADD,
+                        IntOrFloat::IntType => Symbol::INT_ADD,
+                    },
+                    _ => symbol,
+                }
+            };
 
             match from_can(env, loc_expr.value, procs, None) {
                 Expr::Load(proc_name) => {
                     // Some functions can potentially mutate in-place.
                     // If we have one of those, switch to the in-place version if appropriate.
-                    match proc_name {
+                    match specialize_builtin_functions(proc_name, &env.subs) {
                         Symbol::LIST_SET => {
                             let subs = &env.subs;
                             // The first arg is the one with the List in it.
@@ -302,7 +312,9 @@ fn from_can<'a>(
                                 _ => call_by_name(env, procs, proc_name, loc_args),
                             }
                         }
-                        _ => call_by_name(env, procs, proc_name, loc_args),
+                        specialized_proc_symbol => {
+                            call_by_name(env, procs, specialized_proc_symbol, loc_args)
+                        }
                     }
                 }
                 ptr => {
diff --git a/compiler/mono/tests/test_mono.rs b/compiler/mono/tests/test_mono.rs
index 04e8156933..47a7efedce 100644
--- a/compiler/mono/tests/test_mono.rs
+++ b/compiler/mono/tests/test_mono.rs
@@ -78,6 +78,49 @@ mod test_mono {
         compiles_to("0.5", Float(0.5));
     }
 
+    #[test]
+    fn float_addition() {
+        compiles_to(
+            "3.0 + 4",
+            CallByName(
+                Symbol::FLOAT_ADD,
+                &[
+                    (Float(3.0), Layout::Builtin(Builtin::Float64)),
+                    (Float(4.0), Layout::Builtin(Builtin::Float64)),
+                ],
+            ),
+        );
+    }
+
+    #[test]
+    fn int_addition() {
+        compiles_to(
+            "0xDEADBEEF + 4",
+            CallByName(
+                Symbol::INT_ADD,
+                &[
+                    (Int(3735928559), Layout::Builtin(Builtin::Int64)),
+                    (Int(4), Layout::Builtin(Builtin::Int64)),
+                ],
+            ),
+        );
+    }
+
+    #[test]
+    fn num_addition() {
+        // Default to Int for `Num *`
+        compiles_to(
+            "3 + 5",
+            CallByName(
+                Symbol::INT_ADD,
+                &[
+                    (Int(3), Layout::Builtin(Builtin::Int64)),
+                    (Int(5), Layout::Builtin(Builtin::Int64)),
+                ],
+            ),
+        );
+    }
+
     #[test]
     fn bool_literal() {
         let arena = Bump::new();