diff --git a/ChangeLog b/ChangeLog
index be3e100f..23b68729 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-08-21  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* src/grpconv.c: Use Basename for the definition of Prog. Prog
+	needs a file visibility.
+	* src/grpunconv.c: Likewise.
+
 2008-08-20  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/chfn.c: Do not exit on pw_unlock failures.
diff --git a/src/grpconv.c b/src/grpconv.c
index a245a400..f3dae8db 100644
--- a/src/grpconv.c
+++ b/src/grpconv.c
@@ -53,8 +53,9 @@
 /*
  * Global variables
  */
-static bool gr_locked   = false;
+static bool gr_locked  = false;
 static bool sgr_locked = false;
+static char *Prog;
 
 /* local function prototypes */
 static void fail_exit (int);
@@ -86,7 +87,8 @@ int main (int argc, char **argv)
 	struct group grent;
 	const struct sgrp *sg;
 	struct sgrp sgent;
-	char *Prog = argv[0];
+
+	Prog = Basename (argv[0]);
 
 	(void) setlocale (LC_ALL, "");
 	(void) bindtextdomain (PACKAGE, LOCALEDIR);
diff --git a/src/grpunconv.c b/src/grpunconv.c
index 18bf3c5c..8ed8db0c 100644
--- a/src/grpunconv.c
+++ b/src/grpunconv.c
@@ -54,8 +54,9 @@
 /*
  * Global variables
  */
-static bool gr_locked   = false;
+static bool gr_locked  = false;
 static bool sgr_locked = false;
+static char *Prog;
 
 /* local function prototypes */
 static void fail_exit (int status);
@@ -86,7 +87,8 @@ int main (int argc, char **argv)
 	const struct group *gr;
 	struct group grent;
 	const struct sgrp *sg;
-	char *Prog = argv[0];
+
+	Prog = Basename (argv[0]);
 
 	(void) setlocale (LC_ALL, "");
 	(void) bindtextdomain (PACKAGE, LOCALEDIR);