diff --git a/.appveyor.yml b/.appveyor.yml
index bae2b08099..65fc9aa413 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -19,8 +19,7 @@ install:
 build: false
 
 test_script:
-  - cargo test --target %TARGET%
-  - cargo test --target %TARGET% --release
+  - C:\msys64\usr\bin\sh ci\run.sh
 
 branches:
   only:
diff --git a/ci/run.sh b/ci/run.sh
index 5995bcbc6a..bc21f548c2 100755
--- a/ci/run.sh
+++ b/ci/run.sh
@@ -2,5 +2,8 @@
 
 set -ex
 
+# FIXME(rust-lang/rust#45201) shouldn't need to specify one codegen unit
+export RUSTFLAGS="$RUSTFLAGS -C codegen-units=1"
+
 cargo test --target $TARGET
 cargo test --release --target $TARGET