diff --git a/src/errorAndExit.c b/src/errorAndExit.c
index b0aece6..3c4d966 100644
--- a/src/errorAndExit.c
+++ b/src/errorAndExit.c
@@ -5,7 +5,7 @@
 
 void errorAndExit() {
   fprintf(stderr, "\nUsage:\n");
-  fprintf(stderr, "  ./patch-installer --disk main.z01 --offset 456z --size 1000 [--keys 123,456,789] [--previous oldfile.tor]\n");
+  fprintf(stderr, "  ./patch-installer --disk main.z01 --offset 456 --size 1000 [--keys 123,456,789] [--previous oldfile.tor]\n");
   fprintf(stderr, "Options:\n");
   fprintf(stderr, "  -d, --disk: The path to the disk file that contains the file we want to extract.\n");
   fprintf(stderr, "  -o, --offset: The offset into the disk, given in bytes, where the local file header of the file we want to extract starts.\n");