diff --git a/src/bootstrap/CHANGELOG.md b/src/bootstrap/CHANGELOG.md
index add73ebd44b..6af57fdd5aa 100644
--- a/src/bootstrap/CHANGELOG.md
+++ b/src/bootstrap/CHANGELOG.md
@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Add options for enabling overflow checks, one for std (`overflow-checks-std`) and one for everything else (`overflow-checks`). Both default to false.
 - Change the names for `dist` commands to match the component they generate. [#90684](https://github.com/rust-lang/rust/pull/90684)
 - The `build.fast-submodules` option has been removed. Fast submodule checkouts are enabled unconditionally. Automatic submodule handling can still be disabled with `build.submodules = false`.
+- Several unsupported `./configure` options have been removed: `optimize`, `parallel-compiler`. These can still be enabled with `--set`, although it isn't recommended.
 
 ### Non-breaking changes
 
diff --git a/src/bootstrap/configure.py b/src/bootstrap/configure.py
index 2fc036082cb..6b139decb55 100755
--- a/src/bootstrap/configure.py
+++ b/src/bootstrap/configure.py
@@ -31,11 +31,10 @@ def v(*args):
     options.append(Option(*args, value=True))
 
 
-o("debug", "rust.debug", "enables debugging environment; does not affect optimization of bootstrapped code (use `--disable-optimize` for that)")
+o("debug", "rust.debug", "enables debugging environment; does not affect optimization of bootstrapped code")
 o("docs", "build.docs", "build standard library documentation")
 o("compiler-docs", "build.compiler-docs", "build compiler documentation")
 o("optimize-tests", "rust.optimize-tests", "build tests with optimizations")
-o("parallel-compiler", "rust.parallel-compiler", "build a multi-threaded rustc")
 o("verbose-tests", "rust.verbose-tests", "enable verbose output when running tests")
 o("ccache", "llvm.ccache", "invoke gcc/clang via ccache to reuse object files between builds")
 o("sccache", None, "invoke gcc/clang via sccache to reuse object files between builds")
@@ -70,7 +69,6 @@ v("llvm-libunwind", "rust.llvm-libunwind", "use LLVM libunwind")
 
 # Optimization and debugging options. These may be overridden by the release
 # channel, etc.
-o("optimize", "rust.optimize", "build optimized rust code")
 o("optimize-llvm", "llvm.optimize", "build optimized LLVM")
 o("llvm-assertions", "llvm.assertions", "build LLVM with assertions")
 o("llvm-plugins", "llvm.plugins", "build LLVM with plugin interface")
@@ -161,7 +159,7 @@ v("default-linker", "rust.default-linker", "the default linker")
 # Many of these are saved below during the "writing configuration" step
 # (others are conditionally saved).
 o("manage-submodules", "build.submodules", "let the build manage the git submodules")
-o("full-bootstrap", "build.full-bootstrap", "build three compilers instead of two")
+o("full-bootstrap", "build.full-bootstrap", "build three compilers instead of two (not recommended except for testing reproducible builds)")
 o("extended", "build.extended", "build an extended rust tool set")
 
 v("tools", None, "List of extended tools will be installed")
@@ -493,4 +491,3 @@ with bootstrap.output('Makefile') as f:
 
 p("")
 p("run `python {}/x.py --help`".format(rust_dir))
-p("")
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
index 7651947c525..13d440423b2 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
@@ -35,7 +35,6 @@ ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
       --enable-debug \
       --enable-lld \
-      --enable-optimize \
       --set llvm.use-linker=lld \
       --set target.x86_64-unknown-linux-gnu.linker=clang \
       --set target.x86_64-unknown-linux-gnu.cc=clang \
diff --git a/src/ci/docker/scripts/musl.sh b/src/ci/docker/scripts/musl.sh
index 65e15950559..3e5dc4af04a 100644
--- a/src/ci/docker/scripts/musl.sh
+++ b/src/ci/docker/scripts/musl.sh
@@ -33,7 +33,7 @@ if [ ! -d $MUSL ]; then
 fi
 
 cd $MUSL
-./configure --enable-optimize --enable-debug --disable-shared --prefix=/musl-$TAG "$@"
+./configure --enable-debug --disable-shared --prefix=/musl-$TAG "$@"
 if [ "$TAG" = "i586" -o "$TAG" = "i686" ]; then
   hide_output make -j$(nproc) AR=ar RANLIB=ranlib
 else
diff --git a/src/ci/run.sh b/src/ci/run.sh
index b0314047c07..16d8bdb8153 100755
--- a/src/ci/run.sh
+++ b/src/ci/run.sh
@@ -132,7 +132,7 @@ trap datecheck EXIT
 SCCACHE_IDLE_TIMEOUT=10800 sccache --start-server || true
 
 if [ "$RUN_CHECK_WITH_PARALLEL_QUERIES" != "" ]; then
-  $SRC/configure --enable-parallel-compiler
+  $SRC/configure --set rust.parallel-compiler
   CARGO_INCREMENTAL=0 $PYTHON ../x.py check
   rm -f config.toml
   rm -rf build