diff --git a/src/preprocess/mod.rs b/src/preprocess/mod.rs
index b7ab1986..917ab5ca 100644
--- a/src/preprocess/mod.rs
+++ b/src/preprocess/mod.rs
@@ -26,6 +26,7 @@ pub struct PreprocessorContext {
     pub renderer: String,
     /// The calling `mdbook` version.
     pub mdbook_version: String,
+    #[serde(skip)]
     __non_exhaustive: (),
 }
 
diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 41176ae0..d31682d4 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -64,6 +64,7 @@ pub struct RenderContext {
     /// renderers to cache intermediate results, this directory is not
     /// guaranteed to be empty or even exist.
     pub destination: PathBuf,
+    #[serde(skip)]
     __non_exhaustive: (),
 }