diff --git a/core/builtin/builtin.odin b/core/builtin/builtin.odin
index 7f5b8cf75..d3679e7cd 100644
--- a/core/builtin/builtin.odin
+++ b/core/builtin/builtin.odin
@@ -100,7 +100,7 @@ offset_of_selector :: proc(selector: $T) -> int ---
 offset_of_member   :: proc($T: typeid, member: $M) -> int ---
 offset_of :: proc{offset_of_selector, offset_of_member}
 // e.g. offset_of(T, "f"), where T can be the type instead of a variable
-offset_of_by_string :: proc($T: typeid, member: string) -> ---
+offset_of_by_string :: proc($T: typeid, member: string) -> int ---
 
 type_of      :: proc(x: expr) -> type ---
 type_info_of :: proc($T: typeid) -> ^runtime.Type_Info ---