diff --git a/ChangeLog b/ChangeLog
index aafef322..caa4f095 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-07-22  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* configure.in, libmisc/shell.c, libmisc/setupenv.c, src/newgrp.c,
+	src/su.c: Let the system shell be configurable.
+
 2009-07-20  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* NEWS, src/su.c, libmisc/shell.c: Added support for shells being a
diff --git a/configure.in b/configure.in
index 0be585b7..861356b3 100644
--- a/configure.in
+++ b/configure.in
@@ -491,6 +491,8 @@ if test "$enable_utmpx" = "yes"; then
 	          [Define if utmpx should be used])
 fi
 
+AC_DEFINE_UNQUOTED(SHELL, [$SHELL], [The default shell.])
+
 AM_GNU_GETTEXT_VERSION(0.16)
 AM_GNU_GETTEXT([external], [need-ngettext])
 AM_CONDITIONAL(USE_NLS, test "x$USE_NLS" = "xyes")
diff --git a/libmisc/setupenv.c b/libmisc/setupenv.c
index 69388136..7d6f7dea 100644
--- a/libmisc/setupenv.c
+++ b/libmisc/setupenv.c
@@ -242,7 +242,7 @@ void setup_env (struct passwd *info)
 	 */
 
 	if ((NULL == info->pw_shell) || ('\0' == *info->pw_shell)) {
-		static char temp_pw_shell[] = "/bin/sh";
+		static char temp_pw_shell[] = SHELL;
 
 		info->pw_shell = temp_pw_shell;
 	}
diff --git a/libmisc/shell.c b/libmisc/shell.c
index 2dd3bb25..4e70505a 100644
--- a/libmisc/shell.c
+++ b/libmisc/shell.c
@@ -85,7 +85,7 @@ int shell (const char *file, /*@null@*/const char *arg, char *const envp[])
 		 * Assume this is a shell script (with no shebang).
 		 * Interpret it with /bin/sh
 		 */
-		execle ("/bin/sh", "sh", file, (char *)0, envp);
+		execle (SHELL, "sh", file, (char *)0, envp);
 		err = errno;
 	}
 
diff --git a/src/newgrp.c b/src/newgrp.c
index e4ea4115..3a03a65c 100644
--- a/src/newgrp.c
+++ b/src/newgrp.c
@@ -722,7 +722,7 @@ int main (int argc, char **argv)
 	 */
 	if (cflag) {
 		closelog ();
-		execl ("/bin/sh", "sh", "-c", command, (char *) 0);
+		execl (SHELL, "sh", "-c", command, (char *) 0);
 #ifdef WITH_AUDIT
 		snprintf (audit_buf, sizeof(audit_buf),
 		          "changing new-gid=%lu", (unsigned long) gid);
@@ -730,7 +730,7 @@ int main (int argc, char **argv)
 		              audit_buf, NULL,
 		              (unsigned int) getuid (), 0);
 #endif
-		perror ("/bin/sh");
+		perror (SHELL);
 		exit ((errno == ENOENT) ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
 	}
 
@@ -757,7 +757,7 @@ int main (int argc, char **argv)
 	} else if ((NULL != pwd->pw_shell) && ('\0' != pwd->pw_shell[0])) {
 		prog = pwd->pw_shell;
 	} else {
-		prog = "/bin/sh";
+		prog = SHELL;
 	}
 
 	/*
diff --git a/src/su.c b/src/su.c
index 3e87425e..c6772a76 100644
--- a/src/su.c
+++ b/src/su.c
@@ -203,7 +203,7 @@ void execve_shell (const char *shellstr, char *args[], char *const envp[])
 			n_args--;
 		}
 
-		(void) execve ("/bin/sh", targs, envp);
+		(void) execve (SHELL, targs, envp);
 	} else {
 		errno = err;
 	}
@@ -724,7 +724,7 @@ int main (int argc, char **argv)
 	 * Set the default shell.
 	 */
 	if ((NULL == shellstr) || ('\0' == shellstr[0])) {
-		shellstr = "/bin/sh";
+		shellstr = SHELL;
 	}
 
 	(void) signal (SIGINT, SIG_IGN);