diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 77adc9fb..5d0bf896 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,10 +15,13 @@ env:
 jobs:
   build_server:
     name: Build server
-    runs-on: ubuntu-latest
+    # Note that this must be kept in sync with the version of Ubuntu which the
+    # Try PureScript server is running, otherwise the server binary may fail to
+    # run.
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
-      
+
       - uses: haskell/actions/setup@v1
         with:
           enable-stack: true
@@ -59,7 +62,10 @@ jobs:
 
   build_client:
     name: Build client
-    runs-on: ubuntu-latest
+    # Note that this must be kept in sync with the version of Ubuntu which the
+    # Try PureScript server is running, otherwise the server binary may fail to
+    # run.
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
@@ -90,7 +96,10 @@ jobs:
 
   release:
     name: Release
-    runs-on: ubuntu-latest
+    # Note that this must be kept in sync with the version of Ubuntu which the
+    # Try PureScript server is running, otherwise the server binary may fail to
+    # run.
+    runs-on: ubuntu-20.04
     if: github.event_name == 'release'
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/deploy/start b/deploy/start
index 4ea236a4..0b4815d4 100755
--- a/deploy/start
+++ b/deploy/start
@@ -2,6 +2,6 @@
 
 set -ex
 set -o noglob
-export XDG_CACHE_HOME=.spago-cache
+export XDG_CACHE_HOME="$PWD/.spago-cache"
 spago install
 exec trypurescript +RTS -N2 -A128m -M3G -RTS 8081 $(spago sources)