diff --git a/core/cfs/cfs-coffee.c b/core/cfs/cfs-coffee.c
index d93bc2f80..e037509a6 100644
--- a/core/cfs/cfs-coffee.c
+++ b/core/cfs/cfs-coffee.c
@@ -215,8 +215,8 @@ get_sector_status(uint16_t sector, struct sector_stats *stats) {
        the following pages as isolated. */
     memset(&hdr, 0, sizeof(hdr));
     hdr.flags = HDR_FLAG_ALLOCATED | HDR_FLAG_ISOLATED;
-    for(page = sector_start; page < skip_pages; page++) {
-      write_header(&hdr, page);
+    for(page = 0; page < skip_pages; page++) {
+      write_header(&hdr, sector_start + page);
     }
     PRINTF("Coffee: Isolated %u pages starting in sector %d\n",
         (unsigned)skip_pages, (int)sector);
@@ -1168,7 +1168,7 @@ cfs_closedir(struct cfs_dir *dir)
 }
 /*---------------------------------------------------------------------------*/
 int
-cfs_coffee_reserve(const char *name, uint32_t size)
+cfs_coffee_reserve(const char *name, cfs_offset_t size)
 {
   return reserve(name, page_count(size), 0) == NULL ? -1 : 0;
 }
@@ -1216,6 +1216,8 @@ cfs_coffee_format(void)
 
   PRINTF("Coffee: Formatting %d sectors", nsectors);
 
+  *next_free = 0;
+
   watchdog_stop();
   for(i = 0; i < nsectors; i++) {
     COFFEE_ERASE(i);
diff --git a/core/cfs/cfs-coffee.h b/core/cfs/cfs-coffee.h
index e8001756e..d511441bf 100644
--- a/core/cfs/cfs-coffee.h
+++ b/core/cfs/cfs-coffee.h
@@ -38,6 +38,8 @@
 #ifndef CFS_COFFEE_H
 #define CFS_COFFEE_H
 
+#include "cfs.h"
+
 /**
  * \file
  *	Header for the Coffee file system.
@@ -59,7 +61,7 @@
  * has been done, files will be set to a default size once opened for
  * the first time.
  */
-int cfs_coffee_reserve(const char *name, uint32_t size);
+int cfs_coffee_reserve(const char *name, cfs_offset_t size);
 
 /**
  * \brief Configure the on-demand log file.
@@ -73,7 +75,7 @@ int cfs_coffee_reserve(const char *name, uint32_t size);
  * is of log_entry_size.
  */
 int cfs_coffee_configure_log(const char *file, unsigned log_size,
-	unsigned log_entry_size);
+                             unsigned log_entry_size);
 
 /**
  * \brief Format the storage area assigned to Coffee.