diff --git a/src/pass.c b/src/pass.c
index 40bca67..2f0000b 100644
--- a/src/pass.c
+++ b/src/pass.c
@@ -393,6 +393,9 @@ int nwipe_random_pass( NWIPE_METHOD_SIGNATURE )
         syncRate = 0;
     }
 
+    /* Select effective I/O block size (e.g. 4 MiB, never smaller than st_blksize). */
+    io_blocksize = nwipe_effective_io_blocksize( c );
+
     /* Compute the per-write sync rate based on io_blocksize and old semantics. */
     syncRate = nwipe_compute_sync_rate_for_device( c, io_blocksize );
 
@@ -411,9 +414,6 @@ int nwipe_random_pass( NWIPE_METHOD_SIGNATURE )
         return -1;
     }
 
-    /* Select effective I/O block size (e.g. 4 MiB, never smaller than st_blksize). */
-    io_blocksize = nwipe_effective_io_blocksize( c );
-
     /*
      * Allocate a generic 16 MiB buffer (by default) that is used as the
      * scratch area for random data. We will only fill and write "blocksize"