diff --git a/biology/libsbml/Makefile b/biology/libsbml/Makefile
index 4e6d0e186774..39e627a55eff 100644
--- a/biology/libsbml/Makefile
+++ b/biology/libsbml/Makefile
@@ -35,7 +35,7 @@ LIBXML2_USE=		GNOME=libxml2
 LIBXML2_USES=		gnome
 PYTHON_BUILD_DEPENDS=	swig:devel/swig
 PYTHON_CMAKE_BOOL=	WITH_PYTHON
-PYTHON_USES=		python
+PYTHON_USES=		python:-3.9
 PYTHON_CMAKE_ON=	WITH_SWIG
 RUBY_BUILD_DEPENDS=	swig:devel/swig
 RUBY_CMAKE_BOOL=	WITH_RUBY