diff --git a/sw/lib/ocaml/ivy/Makefile b/sw/lib/ocaml/ivy/Makefile
index 8d7d35e4e1..e738db897c 100644
--- a/sw/lib/ocaml/ivy/Makefile
+++ b/sw/lib/ocaml/ivy/Makefile
@@ -17,7 +17,7 @@ OCAMLFLAGS =
 endif
 
 OCAMLOPTFLAGS=
-CFLAGS=-Wall
+CFLAGS+=-Wall
 OCAMLINC=-I `ocamlc -where`
 GLIBINC=`pkg-config --cflags glib-2.0`
 
diff --git a/sw/lib/ocaml/ivy/civyloop.c b/sw/lib/ocaml/ivy/civyloop.c
index 529e5dae1f..d774e9923c 100644
--- a/sw/lib/ocaml/ivy/civyloop.c
+++ b/sw/lib/ocaml/ivy/civyloop.c
@@ -25,7 +25,7 @@ value ivy_mainLoop(value unit)
 void timer_cb(TimerId id, void *data, unsigned long delta)
 {
   value closure = *(value*)data;
-  callback(closure, Val_long((int) id));	
+  callback(closure, Val_long(id));	
 }
 
 value ivy_timerRepeatafter(value nb_ticks,value delay, value closure_name)