diff --git a/serde/src/integer128.rs b/serde/src/integer128.rs
index 3028c0ae..0ee05bdc 100644
--- a/serde/src/integer128.rs
+++ b/serde/src/integer128.rs
@@ -10,7 +10,7 @@
 /// bother with this macro and may assume support for 128-bit integers.
 ///
 /// ```edition2018
-/// # use serde::__private::ser::Error;
+/// # use serde::__private::doc::Error;
 /// #
 /// # struct MySerializer;
 /// #
diff --git a/serde/src/private/macros.rs b/serde/src/private/doc.rs
similarity index 89%
rename from serde/src/private/macros.rs
rename to serde/src/private/doc.rs
index 06a9e957..f597af84 100644
--- a/serde/src/private/macros.rs
+++ b/serde/src/private/doc.rs
@@ -1,3 +1,35 @@
+// Used only by Serde doc tests. Not public API.
+
+use lib::*;
+
+use ser;
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub struct Error;
+
+impl ser::Error for Error {
+    fn custom<T>(_: T) -> Self
+    where
+        T: Display,
+    {
+        unimplemented!()
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        unimplemented!()
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
+        unimplemented!()
+    }
+}
+
 #[doc(hidden)]
 #[macro_export]
 macro_rules! __private_serialize {
@@ -10,7 +42,6 @@ macro_rules! __private_serialize {
     };
 }
 
-/// Used only by Serde doc tests. Not public API.
 #[doc(hidden)]
 #[macro_export(local_inner_macros)]
 macro_rules! __serialize_unimplemented {
diff --git a/serde/src/private/mod.rs b/serde/src/private/mod.rs
index 73355e4d..702e981e 100644
--- a/serde/src/private/mod.rs
+++ b/serde/src/private/mod.rs
@@ -1,6 +1,5 @@
-mod macros;
-
 pub mod de;
+pub mod doc;
 pub mod ser;
 
 pub use lib::clone::Clone;
diff --git a/serde/src/private/ser.rs b/serde/src/private/ser.rs
index 1ac9363f..6ee99938 100644
--- a/serde/src/private/ser.rs
+++ b/serde/src/private/ser.rs
@@ -335,33 +335,6 @@ where
     }
 }
 
-/// Used only by Serde doc tests. Not public API.
-#[doc(hidden)]
-#[derive(Debug)]
-pub struct Error;
-
-impl ser::Error for Error {
-    fn custom<T>(_: T) -> Self
-    where
-        T: Display,
-    {
-        unimplemented!()
-    }
-}
-
-#[cfg(feature = "std")]
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        unimplemented!()
-    }
-}
-
-impl Display for Error {
-    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
-        unimplemented!()
-    }
-}
-
 #[cfg(any(feature = "std", feature = "alloc"))]
 mod content {
     use lib::*;
diff --git a/serde/src/ser/impossible.rs b/serde/src/ser/impossible.rs
index 8a6501e5..e8df9ca7 100644
--- a/serde/src/ser/impossible.rs
+++ b/serde/src/ser/impossible.rs
@@ -17,7 +17,7 @@ use ser::{
 ///
 /// ```edition2018
 /// # use serde::ser::{Serializer, Impossible};
-/// # use serde::__private::ser::Error;
+/// # use serde::__private::doc::Error;
 /// #
 /// # struct MySerializer;
 /// #
diff --git a/serde/src/ser/mod.rs b/serde/src/ser/mod.rs
index 1e7ef8ab..d686c5ad 100644
--- a/serde/src/ser/mod.rs
+++ b/serde/src/ser/mod.rs
@@ -711,7 +711,7 @@ pub trait Serializer: Sized {
     ///
     /// ```edition2018
     /// # use serde::ser::{Serializer, SerializeSeq};
-    /// # use serde::__private::ser::Error;
+    /// # use serde::__private::doc::Error;
     /// #
     /// # struct MySerializer;
     /// #