diff --git a/doc/make.py b/doc/make.py
index cc388186f4b8720da6eae5a18f7e7ea019a3ddef..028e781d8450d16d4c22f083f9f59ce8a5a0b9b6 100644
--- a/doc/make.py
+++ b/doc/make.py
@@ -61,5 +61,5 @@ def _CollectRstDocs(outdir, dirname, fnames):
       
 for sub_dir in ('modules',):
   os.path.walk(sub_dir, _CollectRstDocs, 'doc/source')
-os.system('sphinx-build -b html -c %s %s %s' % ('doc/conf', 'doc/source', 
-                                                'doc/build'))
\ No newline at end of file
+os.system('sphinx-build-2.6 -b html -c %s %s %s' % ('doc/conf', 'doc/source', 
+                                                'doc/build'))