diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc74a5111..92cacf5bc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -37,7 +37,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [beta, 1.56.1]
+        rust: [beta, 1.64.0, 1.56.1]
         os: [ubuntu]
         include:
           - rust: stable
@@ -52,16 +52,18 @@ jobs:
         with:
           toolchain: ${{matrix.rust}}
           targets: ${{matrix.target}}
-      - run: cargo check
-      - run: cargo check --features float_roundtrip
-      - run: cargo check --features arbitrary_precision
-      - run: cargo check --features raw_value
-      - run: cargo check --features unbounded_depth
+      - run: cargo check --manifest-path tests/crate/Cargo.toml
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --features float_roundtrip
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --features arbitrary_precision
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --features raw_value
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --features unbounded_depth
       - 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,arbitrary_precision
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,raw_value
-      - run: cargo check --features preserve_order
-      - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,preserve_order
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --features serde_json/preserve_order
+        if: matrix.rust != '1.56.1'
+      - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,serde_json/preserve_order
+        if: matrix.rust != '1.56.1'
       - name: Build without std
         run: cargo check --manifest-path tests/crate/Cargo.toml --target ${{matrix.target}} --no-default-features --features alloc
         if: matrix.target
@@ -119,5 +121,5 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/install@cargo-outdated
-      - run: cargo outdated --workspace --exit-code 1
+      - run: cargo outdated --exit-code 1
       - run: cargo outdated --manifest-path fuzz/Cargo.toml --exit-code 1
diff --git a/Cargo.toml b/Cargo.toml
index 09fb908ca..af0c3047e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,7 +13,7 @@ rust-version = "1.36"
 
 [dependencies]
 serde = { version = "1.0.100", default-features = false }
-indexmap = { version = "1.5.2", features = ["std"], optional = true }
+indexmap = { version = "2", optional = true }
 itoa = "1.0"
 ryu = "1.0"
 
@@ -28,9 +28,6 @@ serde_derive = "1.0"
 serde_stacker = "0.1"
 trybuild = { version = "1.0.49", features = ["diff"] }
 
-[workspace]
-members = ["tests/crate"]
-
 [lib]
 doc-scrape-examples = false
 
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index 8e925bf94..5fe38b679 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -17,5 +17,3 @@ name = "from_slice"
 path = "fuzz_targets/from_slice.rs"
 test = false
 doc = false
-
-[workspace]
diff --git a/tests/crate/Cargo.toml b/tests/crate/Cargo.toml
index 6a3ac7034..03fde9c44 100644
--- a/tests/crate/Cargo.toml
+++ b/tests/crate/Cargo.toml
@@ -15,7 +15,8 @@ serde_json = { path = "../..", default-features = false }
 default = ["std"]
 std = ["serde_json/std"]
 alloc = ["serde_json/alloc"]
-preserve_order = ["serde_json/preserve_order"]
+#preserve_order = ["serde_json/preserve_order"]
+float_roundtrip = ["serde_json/float_roundtrip"]
 arbitrary_precision = ["serde_json/arbitrary_precision"]
 raw_value = ["serde_json/raw_value"]
 unbounded_depth = ["serde_json/unbounded_depth"]