diff --git a/Makefile.in b/Makefile.in
index 0c1d9e1..7ea5ef9 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -120,7 +120,7 @@
 	dd if=/dev/urandom bs=56 count=1 of=piler.key
 
 postinstall:
-	@sh util/postinstall.sh $(RUNNING_USER) $(RUNNING_GROUP) $(sysconfdir) $(localstatedir) $(libexecdir)
+	@bash util/postinstall.sh $(RUNNING_USER) $(RUNNING_GROUP) $(sysconfdir) $(localstatedir) $(libexecdir)