diff --git a/.bazelrc b/.bazelrc
index 5c9525c20..2e841bfbf 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -26,9 +26,17 @@ test --test_output=errors
 # don't add empty __init__.py files
 build --incompatible_default_to_explicit_init_py
 
-# faster for .ui file generation, but may sacrifice correctness
-#--genrule_strategy=standalone
-
 build:ci --show_timestamps --isatty=0 --color=yes --show_progress_rate_limit=5
 
+# incrementally compile Anki crates in fastbuild mode, but not release mode.
+# The worker must be separately enabled; see docs/development.md
+build -c fastbuild --@rules_rust//worker:include_regex=anki.*|rsbridge
+build:opt -c opt --@rules_rust//worker:include_regex=no-crates-please
+build --worker_max_instances=Rustc=HOST_CPUS*0.5
+
+# the TypeScript workers on Windows choke when deps are changed while they're
+# still running, so shut them down at the end of the build. Also fixes issues
+# with the optional Rust worker.
+build:windows --worker_quit_after_build
+
 try-import %workspace%/user.bazelrc
diff --git a/docs/development.md b/docs/development.md
index 6735bd475..c9a53ef38 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -149,11 +149,11 @@ build --disk_cache=~/bazel/ankidisk --repository_cache=~/bazel/ankirepo
 ```
 
 If you're frequently modifying the Rust parts of Anki, you can place the
-following in your user.bazelrc file to enable incremental compilation:
+following in your user.bazelrc file to enable incremental compilation
+when using ./run.
 
 ```
-build --@rules_rust//worker:use_worker=True
-build:windows --worker_quit_after_build
+build --@rules_rust//worker:cache_root=/path/to/folder/to/store/temp/files
 ```
 
 The worker support is experimental, so you may need to remove it in future
diff --git a/repos.bzl b/repos.bzl
index e60055496..836ac670b 100644
--- a/repos.bzl
+++ b/repos.bzl
@@ -33,11 +33,11 @@ def register_repos():
     maybe(
         http_archive,
         name = "rules_rust",
-        strip_prefix = "rules_rust-anki-2021-03-27-2",
+        strip_prefix = "rules_rust-anki-2021-03-30",
         urls = [
-            "https://github.com/ankitects/rules_rust/archive/anki-2021-03-27-2.tar.gz",
+            "https://github.com/ankitects/rules_rust/archive/anki-2021-03-30.tar.gz",
         ],
-        sha256 = "435cbefb4154a51f2f019c831a9ec3248724a90415f13858030562b14d6416bf",
+        sha256 = "ad6286615fd21f71db4490207aa8d5ecdf5f526643cd65d682458d92aa84ff85",
     )
 
     # python
diff --git a/scripts/build b/scripts/build
index 19acc7aa7..ae2b2f45b 100755
--- a/scripts/build
+++ b/scripts/build
@@ -8,5 +8,5 @@ test -e WORKSPACE || (
 )
 
 rm -rf bazel-dist
-bazel build -c opt --@rules_rust//worker:use_worker=False dist
+bazel build --config opt dist
 tar xvf bazel-bin/dist.tar
diff --git a/scripts/runopt b/scripts/runopt
index a8156e1bc..5663c58cd 100755
--- a/scripts/runopt
+++ b/scripts/runopt
@@ -2,4 +2,4 @@
 
 set -e
 
-BUILDARGS="-c opt --@rules_rust//worker:use_worker=False" $(dirname $0)/../run $*
+BUILDARGS="--config opt" $(dirname $0)/../run $*