diff --git a/docs/Makefile b/docs/Makefile
index 80fe3d3..3262e46 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,7 +3,11 @@
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
+ifeq ($(wildcard sphinx-build), )
+	SPHINXBUILD   = sphinx-build
+else
+	SPHINXBUILD   = ./sphinx-build
+endif
 PAPER         =
 BUILDDIR      = _build