diff --git a/runtime/runtime.c b/runtime/runtime.c
index 78b992287..bd8c5fb25 100644
--- a/runtime/runtime.c
+++ b/runtime/runtime.c
@@ -790,7 +790,7 @@ extern int Lwrite (int n) {
 
 /* GC starts here */
 
-extern const size_t __gc_data_end, __gc_data_start;
+extern const size_t __start_custom_data, __stop_custom_data;
 
 # ifdef __ENABLE_GC__
 
@@ -1004,8 +1004,8 @@ extern void gc_test_and_copy_root (size_t ** root) {
 }
 
 extern void gc_root_scan_data (void) {
-  size_t * p = &__gc_data_start;
-  while  (p != &__gc_data_end) {
+  size_t * p = &__start_custom_data;
+  while  (p != &__stop_custom_data) {
     gc_test_and_copy_root (p);
     p++;
   }
diff --git a/src/X86.ml b/src/X86.ml
index c6a478bac..de4c3ef31 100644
--- a/src/X86.ml
+++ b/src/X86.ml
@@ -659,15 +659,12 @@ class env prg =
 let genasm cmd prog =
   let sm        = SM.compile cmd prog in
   let env, code = compile cmd (new env sm) sm in
-  let gc_start, gc_end = "__gc_data_start", "__gc_data_end" in
   let globals =
-    List.map (fun s -> Meta (Printf.sprintf "\t.globl\t%s" s)) ([gc_start; gc_end] @ env#publics)
+    List.map (fun s -> Meta (Printf.sprintf "\t.globl\t%s" s)) env#publics
   in
-  let data = [Meta "\t.data";
-              Meta (Printf.sprintf "filler:\t.fill\t%d, 4, 1" env#max_locals_size);
-              Meta (Printf.sprintf "%s:" gc_start)] @
+  let data = [Meta "\t.section custom_data,\"aw\",@progbits";
+              Meta (Printf.sprintf "filler:\t.fill\t%d, 4, 1" env#max_locals_size)] @
               (List.map (fun s -> Meta (Printf.sprintf "%s:\t.int\t1" s)) env#globals) @
-              [Meta (Printf.sprintf "%s:" gc_end)] @
               (List.map (fun (s, v) -> Meta (Printf.sprintf "%s:\t.string\t\"%s\"" v s)) env#strings)
   in
   let asm = Buffer.create 1024 in