diff -rupN a/docs/CMakeLists.txt b/docs/CMakeLists.txt
--- a/docs/CMakeLists.txt	2016-06-01 09:50:24.174184477 -0700
+++ b/docs/CMakeLists.txt	2016-06-01 09:51:02.687901780 -0700
@@ -1,7 +1,7 @@
 add_subdirectory(tools)
 
 find_program(SPHINX_EXECUTABLE
-  NAMES sphinx-build
+  NAMES sphinx-build2
   HINTS $ENV{SPHINX_DIR}
   PATH_SUFFIXES bin
   DOC "Sphinx documentation generator")
@@ -10,7 +10,6 @@ SET(SWIFT_SPHINX_PAPER_SIZE "letter"
   CACHE STRING "Paper size for generated documentation")
 
 SET(SPHINX_ARGS
-  -W
   -D latex_paper_size=${SWIFT_SPHINX_PAPER_SIZE}
   -d ${CMAKE_BINARY_DIR}/doctrees)