diff --git a/.gitignore b/.gitignore
index f5d7bb8..74ad10a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,4 @@ config.status
 *.bbl
 auto
 autom4te.cache
+!/lib/c/*.h
diff --git a/compiler/obc/c/async_avr.ml b/compiler/obc/c/async_avr.ml
index ff7baab..0f37fa9 100644
--- a/compiler/obc/c/async_avr.ml
+++ b/compiler/obc/c/async_avr.ml
@@ -31,4 +31,22 @@ struct
 
   let gen_copy_func_out cd = gen_copy_func cd "_out"
 
+  let includes = ["avr"]
+
+  let decls_and_defs classes =
+    (* run_timers is declared in avr.h (because of the ISR macro which
+     * I don't know how to generate here) *)
+    let defs = [
+      Cfundef {
+        C.f_name = "run_timers";
+        f_retty = Cty_void;
+        f_args = [];
+        f_body = {
+          var_decls = [];
+          block_body = []
+        }
+      }
+    ] in
+    [], defs
+
 end
diff --git a/compiler/obc/c/async_backend.mli b/compiler/obc/c/async_backend.mli
index 90ce29b..8639efc 100644
--- a/compiler/obc/c/async_backend.mli
+++ b/compiler/obc/c/async_backend.mli
@@ -5,4 +5,6 @@ module type AsyncBackend =
 sig
   val gen_copy_func_in : class_def -> cdef
   val gen_copy_func_out : class_def -> cdef
+  val includes : string list
+  val decls_and_defs : class_def list -> cdecl list * cdef list
 end
diff --git a/compiler/obc/c/cgen.ml b/compiler/obc/c/cgen.ml
index 8c19269..43086e2 100644
--- a/compiler/obc/c/cgen.ml
+++ b/compiler/obc/c/cgen.ml
@@ -1080,9 +1080,14 @@ let global_file_header name prog =
         | s -> s ^ "_types")
       dependencies in
 
+  let dependencies_types = AvrBackend.includes @ dependencies_types in
+
   let classes = program_classes prog in
-  let (decls, defs) =
-    List.split (List.map cdefs_and_cdecls_of_class_def classes) in
+  let decls_and_defs = List.map cdefs_and_cdecls_of_class_def classes in
+  let decls_and_defs =
+    (AvrBackend.decls_and_defs classes) :: decls_and_defs
+  in
+  let (decls, defs) = List.split decls_and_defs in
   let decls = List.concat decls
   and defs = List.concat defs in
 
diff --git a/lib/c/avr.h b/lib/c/avr.h
new file mode 100644
index 0000000..acd5931
--- /dev/null
+++ b/lib/c/avr.h
@@ -0,0 +1,52 @@
+/***********************************************************************/
+/*                                                                     */
+/*                             Heptagon                                */
+/*                                                                     */
+/* Gwenael Delaval, LIG/INRIA, UJF                                     */
+/* Leonard Gerard, Parkas, ENS                                         */
+/* Adrien Guatto, Parkas, ENS                                          */
+/* Cedric Pasteur, Parkas, ENS                                         */
+/* Marc Pouzet, Parkas, ENS                                            */
+/*                                                                     */
+/* Copyright 2012 ENS, INRIA, UJF                                      */
+/*                                                                     */
+/* This file is part of the Heptagon compiler.                         */
+/*                                                                     */
+/* Heptagon is free software: you can redistribute it and/or modify it */
+/* under the terms of the GNU General Public License as published by   */
+/* the Free Software Foundation, either version 3 of the License, or   */
+/* (at your option) any later version.                                 */
+/*                                                                     */
+/* Heptagon is distributed in the hope that it will be useful,         */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of      */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the       */
+/* GNU General Public License for more details.                        */
+/*                                                                     */
+/* You should have received a copy of the GNU General Public License   */
+/* along with Heptagon.  If not, see <http://www.gnu.org/licenses/>    */
+/*                                                                     */
+/***********************************************************************/
+
+/* Pervasives module for the Heptagon compiler */
+
+#ifndef DECADES_AVR_H
+#define DECADES_AVR_H
+#ifdef __AVR__
+#include <util/atomic.h>
+#include <avr/interrupt.h>
+
+void run_timers();
+
+ISR(TIMER0_OVF_vect) {
+  run_timers();
+}
+
+static inline void atomic_memcpy(void *dest, const void *src, size_t size) {
+  ATOMIC_BLOCK(ATOMIC_FORCEON) {
+    memcpy(dest, src, size);
+  }
+}
+
+#endif
+#endif
+
diff --git a/lib/c/pervasives.h b/lib/c/pervasives.h
index 0b4db76..720f3f1 100644
--- a/lib/c/pervasives.h
+++ b/lib/c/pervasives.h
@@ -32,9 +32,6 @@
 #ifndef DECADES_PERVASIVES_H
 #define DECADES_PERVASIVES_H
 #include <string.h>
-#ifdef __AVR__
-#include <util/atomic.h>
-#endif
 
 typedef float real;
 
@@ -45,13 +42,5 @@ static inline int between(int idx, int n)
   return o;
 }
 
-#ifdef __AVR__
-static inline void atomic_memcpy(void *dest, const void *src, size_t size) {
-  ATOMIC_BLOCK(ATOMIC_FORCEON) {
-    memcpy(dest, src, size);
-  }
-}
-#endif
-
 #endif