--- a/Makefile.in
+++ b/Makefile.in
@@ -65,7 +65,7 @@
 always:

 version.h: always
-	bash mkversion.sh
+	$(SHELL) mkversion.sh

 $(TARGET): $(OBJECTS)
	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJECTS) $(LIBS) -o $@