diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index e36ef83f8c..d83b830028 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -95,7 +95,7 @@ jobs:
 
       - name: Build module
         run: |
-            python3 -m pip install -e . --install-option="--disable_lto"
+            python -m pip install -e .
 
       - name: Build the docs
         working-directory: doc
diff --git a/.github/workflows/manylinux/buildwheels.sh b/.github/workflows/manylinux/buildwheels.sh
index fe5302b97a..fbfe13e298 100644
--- a/.github/workflows/manylinux/buildwheels.sh
+++ b/.github/workflows/manylinux/buildwheels.sh
@@ -13,7 +13,7 @@ source "$HOME/.cargo/env"
 # so we need to be careful in general.
 rustup override set 1.62.1 
 # Pin cbindgen 
-cargo install cbindgen@0.24.3 
+cargo install --locked cbindgen@0.24.3 
 
 # GSL_VERSION=2.5
 # curl -o gsl-${GSL_VERSION}.tar.gz "ftp://ftp.gnu.org/gnu/gsl/gsl-${GSL_VERSION}.tar.gz" 
diff --git a/deployment/docker/Dockerfile b/deployment/docker/Dockerfile
index 2eaeab4520..0bebd208b1 100644
--- a/deployment/docker/Dockerfile
+++ b/deployment/docker/Dockerfile
@@ -28,7 +28,7 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get -qq -y install cmak
   # so we need to be careful in general.
   && rustup override set 1.62.1 \
   # Pin cbindgen 
-  && cargo install cbindgen@0.24.3 \
+  && cargo install --locked cbindgen@0.24.3 \
   && rustc --version \
   && cbindgen --version \
   && ls -lhrt
diff --git a/doc/misc/changelog.md b/doc/misc/changelog.md
index 2fec311485..c0c63a4f9d 100644
--- a/doc/misc/changelog.md
+++ b/doc/misc/changelog.md
@@ -3,6 +3,13 @@
 Major changes are listed below.  Each release likely contains fiddling with back-end code,
 updates to latest `fwdpp` version, etc.
 
+## 0.20.1
+
+Build system and CI.
+
+* Update pip usage and ensure reproducible builds of rust code.
+  PR {pr}`1156`
+
 ## 0.20.0
 
 Documentation
diff --git a/rust/fp11rust/Cargo.lock b/rust/fp11rust/Cargo.lock
new file mode 100644
index 0000000000..721e06a372
--- /dev/null
+++ b/rust/fp11rust/Cargo.lock
@@ -0,0 +1,249 @@
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