diff --git a/x11-toolkits/gtkada/Makefile b/x11-toolkits/gtkada/Makefile
index 1e8faa0fc887..5bc7e68836e0 100644
--- a/x11-toolkits/gtkada/Makefile
+++ b/x11-toolkits/gtkada/Makefile
@@ -34,7 +34,8 @@ OPTIONS_DEFINE=		DOCS NLS EXAMPLES
 .include <bsd.port.options.mk>
 
 .if ${PORT_OPTIONS:MDOCS}
-BUILD_DEPENDS+=	sphinx-build:textproc/py-sphinx
+BUILD_DEPENDS+=	sphinx-build-2.7:textproc/py-sphinx@py27
+BINARY_ALIAS+=	sphinx-build=sphinx-build-2.7
 .endif
 
 .if ${PORT_OPTIONS:MNLS}