--- unstr-orig.c	2022-02-23 10:42:08.896750237 +0100
+++ unstr.c	2022-02-23 10:27:20.292195849 +0100
@@ -231,7 +231,7 @@
 	exit(1);
     }
 #define checked_fread(item, size)                          \
-    if (fread(item, size, 1, Dataf) != size)               \
+    if (fread(item, size, 1, Dataf) != 1)                  \
       {                                                    \
         fprintf(stderr, "unstr: data file corrupted\n");   \
         exit(1);                                           \