diff --git a/library/compiler-builtins/.github/workflows/main.yaml b/library/compiler-builtins/.github/workflows/main.yaml
index 1572a8ec6cd1..3fed58f2a207 100644
--- a/library/compiler-builtins/.github/workflows/main.yaml
+++ b/library/compiler-builtins/.github/workflows/main.yaml
@@ -70,14 +70,14 @@ jobs:
           os: ubuntu-24.04
         - target: powerpc64le-unknown-linux-gnu
           os: ubuntu-24.04
-        - target: powerpc64le-unknown-linux-gnu
-          os: ubuntu-24.04-ppc64le
-          # FIXME(rust#151807): remove once PPC builds work again.
-          channel: nightly-2026-01-23
+        # - target: powerpc64le-unknown-linux-gnu
+        #   os: ubuntu-24.04-ppc64le
+        #   # FIXME(rust#151807): remove once PPC builds work again.
+        #   channel: nightly-2026-01-23
         - target: riscv64gc-unknown-linux-gnu
           os: ubuntu-24.04
-        - target: s390x-unknown-linux-gnu
-          os: ubuntu-24.04-s390x
+        # - target: s390x-unknown-linux-gnu
+        #   os: ubuntu-24.04-s390x
         - target: thumbv6m-none-eabi
           os: ubuntu-24.04
         - target: thumbv7em-none-eabi