--- a/libhfsp/src/fscheck.c
+++ b/libhfsp/src/fscheck.c
@@ -47,6 +47,8 @@
 # include "os.h"
 # include "swab.h"
 
+struct fsck_data_t fsck_data;
+
 /* Dump all raw fork information to stdout */
 void print_fork(hfsp_fork_raw* f)
 {
--- a/libhfsp/src/fscheck.h
+++ b/libhfsp/src/fscheck.h
@@ -100,10 +100,11 @@
 int fscheck_files(volume* vol);
 
 /** global data used during fsck */
-struct {
+struct fsck_data_t {
     UInt32  maxCnid;
     UInt32  macNow; // current date in mac-offset
     int	    verbose;
     int	    ignoreErr;
-} fsck_data;
+};
 
+extern struct fsck_data_t fsck_data;