diff --git a/programs/hash/sha1sum.c b/programs/hash/sha1sum.c
index 954568b..03b7766 100644
--- a/programs/hash/sha1sum.c
+++ b/programs/hash/sha1sum.c
@@ -83,7 +83,7 @@
 
     n = sizeof( line );
 
-    while( fgets( line, n - 1, f ) != NULL )
+    while( fgets( line, (int) n - 1, f ) != NULL )
     {
         n = strlen( line );