diff --git a/docs/development/contributing/index.md b/docs/development/contributing/index.md
index 2aa65ed0fa5e..6296ed9f30b9 100644
--- a/docs/development/contributing/index.md
+++ b/docs/development/contributing/index.md
@@ -253,7 +253,9 @@ The snippet is delimited by `--8<-- [start:<snippet_name>]` and `--8<-- [end:<sn
 
 #### Linting
 
-Before committing, install `dprint` (see above) and run `dprint fmt` from the `docs` directory to lint the markdown files.
+Before committing: 
+- install `dprint` (see above) and run `dprint fmt` from the `docs` directory to lint the markdown files
+- run `cargo fmt` for the `docs` directory to format the Rust code snippets
 
 ### API reference
 
diff --git a/docs/src/rust/user-guide/transformations/concatenation.rs b/docs/src/rust/user-guide/transformations/concatenation.rs
index 0b12b6ebd9de..4675fbff2159 100644
--- a/docs/src/rust/user-guide/transformations/concatenation.rs
+++ b/docs/src/rust/user-guide/transformations/concatenation.rs
@@ -22,21 +22,20 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // --8<-- [start:vertical_relaxed]
     let df_v1 = df!(
-        "a"=> &[1.0],
-        "b"=> &[3],
-)?;
-let df_v2 = df!(
-        "a"=> &[2],
-        "b"=> &[4],
-)?;
-let df_vertical_relaxed_concat = concat(
-    [df_v1.clone().lazy(), df_v2.clone().lazy()],
-    UnionArgs::default(),
-)?
-.collect()?;
-println!("{}", &df_vertical_relaxed_concat);
-// --8<-- [end:vertical_relaxed]
-
+            "a"=> &[1.0],
+            "b"=> &[3],
+    )?;
+    let df_v2 = df!(
+            "a"=> &[2],
+            "b"=> &[4],
+    )?;
+    let df_vertical_relaxed_concat = concat(
+        [df_v1.clone().lazy(), df_v2.clone().lazy()],
+        UnionArgs::default(),
+    )?
+    .collect()?;
+    println!("{}", &df_vertical_relaxed_concat);
+    // --8<-- [end:vertical_relaxed]
 
     // --8<-- [start:horizontal]
     let df_h1 = df!(