diff --git a/serde/Cargo.toml b/serde/Cargo.toml
index d238ededc2..26dbda8727 100644
--- a/serde/Cargo.toml
+++ b/serde/Cargo.toml
@@ -1,7 +1,10 @@
 [package]
 name = "serde"
 version = "1.0.204"
-authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
+authors = [
+    "Erick Tryzelaar <erick.tryzelaar@gmail.com>",
+    "David Tolnay <dtolnay@gmail.com>",
+]
 build = "build.rs"
 categories = ["encoding", "no-std", "no-std::no-alloc"]
 description = "A generic serialization/deserialization framework"
@@ -16,7 +19,7 @@ rust-version = "1.31"
 
 [dependencies]
 serde_derive = { version = "1", optional = true, path = "../serde_derive" }
-serde_core = { version = "=1.0.203", path = "../serde_core", default-features = false }
+serde_core = { version = "=1.0.204", path = "../serde_core", default-features = false }
 
 [dev-dependencies]
 serde_derive = { version = "1", path = "../serde_derive" }
diff --git a/serde_core/Cargo.toml b/serde_core/Cargo.toml
index c54d5f7235..31cd21733f 100644
--- a/serde_core/Cargo.toml
+++ b/serde_core/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "serde_core"
-version = "1.0.203" # remember to update html_root_url and serde_derive dependency
+version = "1.0.204" # remember to update html_root_url and serde_derive dependency
 authors = [
     "Erick Tryzelaar <erick.tryzelaar@gmail.com>",
     "David Tolnay <dtolnay@gmail.com>",
diff --git a/serde_core/build.rs b/serde_core/build.rs
index 46ca435d5c..3263b234e8 100644
--- a/serde_core/build.rs
+++ b/serde_core/build.rs
@@ -25,6 +25,7 @@ fn main() {
         println!("cargo:rustc-check-cfg=cfg(no_std_atomic64)");
         println!("cargo:rustc-check-cfg=cfg(no_systemtime_checked_add)");
         println!("cargo:rustc-check-cfg=cfg(no_target_has_atomic)");
+        println!("cargo:rustc-check-cfg=cfg(no_diagnostic_namespace)");
     }
 
     let target = env::var("TARGET").unwrap();
diff --git a/serde_core/src/lib.rs b/serde_core/src/lib.rs
index 4a9ff6db46..62784bdf10 100644
--- a/serde_core/src/lib.rs
+++ b/serde_core/src/lib.rs
@@ -15,7 +15,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.203")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.204")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Show which crate feature enables conditionally compiled APIs in documentation.