diff --git a/src/rlang/vec.h b/src/rlang/vec.h
index 46db7b02a..78f104028 100644
--- a/src/rlang/vec.h
+++ b/src/rlang/vec.h
@@ -47,12 +47,12 @@ const void* r_raw_cbegin(r_obj* x) {
 }
 static inline
 r_obj* const * r_chr_cbegin(r_obj* x) {
-  return (r_obj* const *) STRING_PTR(x);
+  return STRING_PTR_RO(x);
 }
 static inline
 r_obj* const * r_list_cbegin(r_obj* x) {
 #if (R_VERSION < R_Version(3, 5, 0))
-  return ((r_obj* const *) STRING_PTR(x));
+  return STRING_PTR_RO(x);
 #else
   return ((r_obj* const *) DATAPTR_RO(x));
 #endif