diff --git a/vlib/builtin/builtin.v b/vlib/builtin/builtin.v
index c831eb309a..5272fdaf3d 100644
--- a/vlib/builtin/builtin.v
+++ b/vlib/builtin/builtin.v
@@ -31,7 +31,6 @@ fn on_panic(f fn (int) int) {
 }
 
 pub fn print_backtrace_skipping_top_frames(skipframes int) {
-	/*
 	$if mac {
 		buffer := [100]byteptr
 		nr_ptrs := C.backtrace(*voidptr(buffer), 100)
@@ -78,8 +77,8 @@ pub fn print_backtrace_skipping_top_frames(skipframes int) {
 		}
 	}
 	println('print_backtrace_skipping_top_frames is not implemented on this platform for now...\n')
-	*/
 }
+
 pub fn print_backtrace(){
 	// at the time of backtrace_symbols_fd call, the C stack would look something like this:
 	// 1 frame for print_backtrace_skipping_top_frames
diff --git a/vlib/builtin/cfns.v b/vlib/builtin/cfns.v
index c467b0cbc4..e5f973af86 100644
--- a/vlib/builtin/cfns.v
+++ b/vlib/builtin/cfns.v
@@ -13,8 +13,8 @@ fn C.strlen(s byteptr) int
 
 
 
-//fn C.backtrace(a voidptr, b int) int
-//fn C.backtrace_symbols_fd(voidptr, int, int)
+fn backtrace(a voidptr, b int) int
+fn backtrace_symbols_fd(voidptr, int, int)