diff --git a/README.rst b/README.rst
index 7555b409a..872626fc6 100644
--- a/README.rst
+++ b/README.rst
@@ -158,7 +158,6 @@ In addition to the normal CMake build options (like ``CMAKE_INSTALL_PREFIX``), f
 - Rust_CARGO=path - the path to cargo. If not set, cmake will check $PATH and ~/.cargo/bin
 - Rust_CARGO_TARGET=target - the target to pass to cargo. Set this for cross-compilation.
 - BUILD_DOCS=ON|OFF - whether to build the documentation. This is automatically set to OFF when Sphinx isn't installed.
-- INSTALL_DOCS=ON|OFF - whether to install the docs. This is automatically set to on when BUILD_DOCS is or prebuilt documentation is available (like when building in-tree from a tarball).
 - FISH_USE_SYSTEM_PCRE2=ON|OFF - whether to use an installed pcre2. This is normally autodetected.
 - MAC_CODESIGN_ID=String|OFF - the codesign ID to use on Mac, or "OFF" to disable codesigning.
 - WITH_GETTEXT=ON|OFF - whether to include translations.