diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 54aebea..5c2f56c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -75,8 +75,7 @@ You can read our [full policy](https://www.eff.org/about/opportunities/volunteer
 This one is for maintainers of Rayhunter.
 
 1. Make a PR changing the versions in `Cargo.toml` and other files.
-   This could be automated better but right now it's manual. You can do this easily with sed:
-   `sed -i "" -E 's/x.x.x/y.y.y/g' */Cargo.toml installer-gui/src-tauri/Cargo.toml`
+   This can be done by running `scripts/set-versions.sh VERSION_NUM`.
 
 2. Merge the PR, make a tag, and push the tag to GitHub. Pushing the tag should
    trigger the [release workflow](https://github.com/EFForg/rayhunter/actions/workflows/release.yml).
diff --git a/scripts/set-versions.sh b/scripts/set-versions.sh
new file mode 100755
index 0000000..a4a5ae0
--- /dev/null
+++ b/scripts/set-versions.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+# Sets Rayhunter package versions in preparation for a release.
+#
+# Usage: ./scripts/set-versions.sh VERSION_NUM
+# Example: ./scripts/set-versions.sh 0.12.3
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+
+cd "$PROJECT_DIR"
+
+if [ -z "$1" ]; then
+    echo "Error: Missing required version number argument."
+    exit 1
+fi
+
+SED_COMMAND="s/^version = \".*\"/version = \"$1\"/"
+TOML_FILES=(*/Cargo.toml installer-gui/src-tauri/Cargo.toml)
+
+echo "Updating Cargo.toml files"
+if sed --version > /dev/null 2>&1; then
+    # we have GNU sed
+    sed -i -E "$SED_COMMAND" "${TOML_FILES[@]}"
+else
+    # we have macOS/BSD sed
+    sed -i "" -E "$SED_COMMAND" "${TOML_FILES[@]}"
+fi
+
+echo "Updating Cargo.lock"
+cargo update --workspace