diff --git a/src/common.c b/src/common.c
index 6737c575..9a77b93f 100644
--- a/src/common.c
+++ b/src/common.c
@@ -188,25 +188,6 @@ struct tm *localtime_r(const time_t *timep, struct tm *result)
 }
 #endif
 
-/*@
-  @ decreases number;
-  @ assigns \nothing;
-  @*/
-static unsigned int up2power_aux(const unsigned int number)
-{
-  if(number==0)
-	return 0;
-  else
-	return(1+up2power_aux(number/2));
-}
-
-unsigned int up2power(const unsigned int number)
-{
-  if(number==0)
-    return 1;
-  return (1<<up2power_aux(number-1));
-}
-
 void set_part_name(partition_t *partition, const char *src, const unsigned int max_size)
 {
   unsigned int i;
diff --git a/src/common.h b/src/common.h
index 49d3b32f..e2ee18f4 100644
--- a/src/common.h
+++ b/src/common.h
@@ -525,11 +525,6 @@ struct my_data_struct
   @*/
 void *MALLOC(size_t size);
 
-/*@
-  @ assigns \nothing;
-  @*/
-unsigned int up2power(const unsigned int number);
-
 /*@
   @ requires \valid(partition);
   @ requires valid_partition(partition);
diff --git a/src/fat_adv.c b/src/fat_adv.c
index bd7fde00..5c4bd587 100644
--- a/src/fat_adv.c
+++ b/src/fat_adv.c
@@ -1260,6 +1260,29 @@ static void create_fat_boot_sector(disk_t *disk_car, partition_t *partition, con
   free(newboot);
 }
 
+/*@
+  @ decreases number;
+  @ assigns \nothing;
+  @*/
+static unsigned int up2power_aux(const unsigned int number)
+{
+  if(number==0)
+	return 0;
+  else
+	return(1+up2power_aux(number/2));
+}
+
+/*@
+  @ assigns \nothing;
+  @*/
+static unsigned int up2power(const unsigned int number)
+{
+  if(number==0)
+    return 1;
+  return (1<<up2power_aux(number-1));
+}
+
+
 static int calcul_sectors_per_cluster(const upart_type_t upart_type, const unsigned long int data_size, const unsigned int fat_length, const unsigned int sector_size)
 {
   /* log_info("calcul_sectors_per_cluster data_size=%lu, fat_length=%u, sector_size=%u\n",data_size,fat_length,sector_size); */