index 8fd957f..cdad96e 100644
--- a/makefile.in
+++ b/makefile.in
@@ -47,7 +48,7 @@ mobical: mobical.o libcadical.a makefile $(LIBS)
 	$(COMPILE) -o $@ $< -L. -lcadical
 
 libcadical.a: $(OBJ) makefile
-	ar rc $@ $(OBJ)
+	${AR} rc $@ $(OBJ)
 
 #--------------------------------------------------------------------------#