diff --git a/CMakeLists.txt b/CMakeLists.txt
index 715744239..0ac262dd5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -221,7 +221,6 @@ if (BUILD_DOCS)
   add_custom_command(OUTPUT ${SPHINX_OUTPUT}
     COMMAND ${SPHINX_EXECUTABLE}
       -a -E -q -b html
-      -c "${CMAKE_CURRENT_SOURCE_DIR}/docs"
       "${CMAKE_CURRENT_SOURCE_DIR}"
       "${CMAKE_CURRENT_SOURCE_DIR}/docs/html"
       -w "${CMAKE_CURRENT_SOURCE_DIR}/docs/_sphinx-warnings.txt"
diff --git a/docs/Contributing.rst b/docs/Contributing.rst
index 343c2de7d..5691fbcc0 100644
--- a/docs/Contributing.rst
+++ b/docs/Contributing.rst
@@ -121,7 +121,7 @@ Documentation Standards
 DFHack documentation is built with Sphinx, and configured automatically
 through CMake.  If you want to build the docs *only*, use this command::
 
-    sphinx-build -a -c docs . docs/html
+    sphinx-build . docs/html
 
 Whether you're adding new code or just fixing old documentation (and there's plenty),
 there are a few important standards for completeness and consistent style.  Treat