diff --git a/CMakeLists.txt b/CMakeLists.txt
index 08962a4d3..e283fb706 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -206,7 +206,7 @@ if (BUILD_DOCS)
     "${CMAKE_CURRENT_SOURCE_DIR}/docs/*.rst"
     "${CMAKE_CURRENT_SOURCE_DIR}/docs/images/*.png"
     "${CMAKE_CURRENT_SOURCE_DIR}/docs/styles/*"
-    "${CMAKE_CURRENT_SOURCE_DIR}/docs/conf.py"
+    "${CMAKE_CURRENT_SOURCE_DIR}/conf.py"
     "${CMAKE_CURRENT_SOURCE_DIR}/scripts/about.txt"
     "${CMAKE_CURRENT_SOURCE_DIR}/scripts/*/about.txt"
   )
@@ -224,6 +224,7 @@ if (BUILD_DOCS)
       "${CMAKE_CURRENT_SOURCE_DIR}"
       "${CMAKE_CURRENT_SOURCE_DIR}/docs/html"
       -w "${CMAKE_CURRENT_SOURCE_DIR}/docs/_sphinx-warnings.txt"
+      -j 2
     DEPENDS ${SPHINX_DEPS}
     COMMENT "Building HTML documentation with Sphinx"
   )
diff --git a/conf.py b/conf.py
index 81cfb78ef..17df22ee4 100644
--- a/conf.py
+++ b/conf.py
@@ -173,7 +173,7 @@ language = None
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ['docs/_build/*', 'depends/*', 'scripts/3rdparty/*']
+exclude_patterns = ['docs/_build/*', 'depends/*', 'scripts/3rdparty/*', 'build*']
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.