diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index f1a4d5f2d..22b777311 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -233,28 +233,26 @@ jobs:
           cargo update -p aws-sdk-sso --precise 1.62.0
           cargo update -p aws-sdk-ssooidc --precise 1.63.0
           cargo update -p aws-sdk-sts --precise 1.63.0
-          # aws-runtime/sigv4/credential-types and the aws-smithy-* crates
-          # bumped their MSRV to 1.91.1 in late 2026; pin to the last
-          # 1.91.0-compatible versions. Order matters: aws-runtime / aws-sigv4
-          # / aws-credential-types are downgraded before the aws-smithy-*
-          # cluster so the constraint chain through aws-smithy-checksums →
-          # aws-smithy-http → aws-smithy-runtime-api / aws-smithy-types can
-          # actually unwind.
+          # aws-runtime/sigv4/credential-types/types and the aws-smithy-*
+          # crates bumped their MSRV to 1.91.1 in late 2026; pin to the last
+          # 1.91.0-compatible versions. The order matters — each downgrade
+          # only succeeds once everything that still pins it at a higher
+          # version has itself been downgraded.
           cargo update -p aws-runtime --precise 1.5.12
+          cargo update -p aws-types --precise 1.3.9
           cargo update -p aws-sigv4 --precise 1.3.5
           cargo update -p aws-credential-types --precise 1.2.8
           cargo update -p aws-smithy-checksums --precise 0.63.9
           cargo update -p aws-smithy-runtime --precise 1.9.3
           cargo update -p aws-smithy-http --precise 0.62.4
           cargo update -p aws-smithy-eventstream --precise 0.60.12
-          cargo update -p aws-smithy-runtime-api --precise 1.9.1
-          cargo update -p aws-smithy-async --precise 1.2.6
-          cargo update -p aws-smithy-types --precise 1.3.5
           cargo update -p aws-smithy-http-client --precise 1.1.3
           cargo update -p aws-smithy-observability --precise 0.1.4
           cargo update -p aws-smithy-query --precise 0.60.8
+          cargo update -p aws-smithy-runtime-api --precise 1.9.1
+          cargo update -p aws-smithy-async --precise 1.2.6
+          cargo update -p aws-smithy-types --precise 1.3.5
           cargo update -p aws-smithy-xml --precise 0.60.11
-          cargo update -p aws-types --precise 1.3.9
           cargo update -p home --precise 0.5.9
       - name: cargo +${{ matrix.msrv }} check
         env: