diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5a4bd7bfd42..2c97c681fa4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -275,16 +275,16 @@ jobs:
             os: ubuntu-20.04-8core-32gb
             env: {}
           - name: x86_64-gnu
-            os: ubuntu-20.04-8core-32gb
+            os: ubuntu-20.04-4core-16gb
             env: {}
           - name: x86_64-gnu-stable
             env:
               IMAGE: x86_64-gnu
               RUST_CI_OVERRIDE_RELEASE_CHANNEL: stable
               CI_ONLY_WHEN_CHANNEL: nightly
-            os: ubuntu-20.04-8core-32gb
+            os: ubuntu-20.04-4core-16gb
           - name: x86_64-gnu-aux
-            os: ubuntu-20.04-8core-32gb
+            os: ubuntu-20.04-4core-16gb
             env: {}
           - name: x86_64-gnu-debug
             os: ubuntu-20.04-8core-32gb
@@ -309,7 +309,7 @@ jobs:
               RUST_BACKTRACE: 1
             os: ubuntu-20.04-8core-32gb
           - name: x86_64-gnu-nopt
-            os: ubuntu-20.04-8core-32gb
+            os: ubuntu-20.04-4core-16gb
             env: {}
           - name: x86_64-gnu-tools
             env:
diff --git a/src/ci/github-actions/ci.yml b/src/ci/github-actions/ci.yml
index db79358aa35..967703ae582 100644
--- a/src/ci/github-actions/ci.yml
+++ b/src/ci/github-actions/ci.yml
@@ -435,7 +435,7 @@ jobs:
             <<: *job-linux-8c
 
           - name: x86_64-gnu
-            <<: *job-linux-8c
+            <<: *job-linux-4c
 
           # This job ensures commits landing on nightly still pass the full
           # test suite on the stable channel. There are some UI tests that
@@ -450,10 +450,10 @@ jobs:
               # could cause failures when `dev: 1` in `stage0.txt`, and running
               # this on stable is useless.
               CI_ONLY_WHEN_CHANNEL: nightly
-            <<: *job-linux-8c
+            <<: *job-linux-4c
 
           - name: x86_64-gnu-aux
-            <<: *job-linux-8c
+            <<: *job-linux-4c
 
           - name: x86_64-gnu-debug
             <<: *job-linux-8c
@@ -482,7 +482,7 @@ jobs:
             <<: *job-linux-8c
 
           - name: x86_64-gnu-nopt
-            <<: *job-linux-8c
+            <<: *job-linux-4c
 
           - name: x86_64-gnu-tools
             env: