diff --git a/math/convertall/Makefile b/math/convertall/Makefile
index 78e22e543286..fbdc31744855 100644
--- a/math/convertall/Makefile
+++ b/math/convertall/Makefile
@@ -18,7 +18,7 @@ RUN_DEPENDS=	pyuic:${PORTSDIR}/x11-toolkits/py-qt
 
 WRKSRC=		${WRKDIR}/ConvertAll
 USE_REINPLACE=	yes
-USE_PYTHON=	yes
+USE_PYTHON=	2.4+
 USE_X_PREFIX=	yes
 NO_BUILD=	yes
 PORTDOCS=	README.html INSTALL LICENSE