diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7d05f283d..4d042de7a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,7 +30,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [beta, stable, 1.45.0, 1.40.0, 1.36.0, 1.31.0]
+        rust: [beta, stable, 1.45.0, 1.40.0, 1.38.0, 1.31.0]
         os: [ubuntu]
         include:
           - rust: stable
@@ -43,6 +43,8 @@ jobs:
       - run: cargo check
       - run: cargo check --features preserve_order
         if: matrix.rust != '1.31.0'
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,preserve_order
+        if: matrix.rust != '1.31.0'
       - run: cargo check --features float_roundtrip
       - run: cargo check --features arbitrary_precision
       - run: cargo check --features raw_value
@@ -64,7 +66,6 @@ jobs:
       - uses: actions/checkout@v2
       - uses: dtolnay/rust-toolchain@1.36.0
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc
-      - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,preserve_order
 
   clippy:
     name: Clippy