1 files changed, 4 insertions, 1 deletions

diff --git a/src/export/extract_version_3.c b/src/export/extract_version_3.c
index fef4241..19df167 100644
--- a/src/export/extract_version_3.c
+++ b/src/export/extract_version_3.c
@@ -10,7 +10,10 @@
 #define HUGEBLOCK (1024*1024)
 
 int main(int argc, char **argv) {
-  MAP in = map_file( argv[1], 1 );
+  MAP in;
+
+  if( argc != 2 ) exit(111);
+  in = map_file( argv[1], 1 );
 
   unsigned const char xorkey [XORLEN] = "Just for Fun. Linus Torvalds.";
   unsigned char input  [XORLEN];