diff --git a/justfile b/justfile
index ea05c45..4d268dd 100644
--- a/justfile
+++ b/justfile
@@ -49,6 +49,9 @@ shellcheck:
 nix:
   @nix flake update
 
+todo:
+  @rg -g '!justfile' todo
+
 logo:
   @cd extra && python logo.py
   @cd extra && magick -background none logo.svg -resize 5000x5000 logo.png
diff --git a/notes.org b/notes.org
index e9afea6..7f87876 100644
--- a/notes.org
+++ b/notes.org
@@ -1,4 +1,6 @@
 #+title: tex-fmt
+* Tasks
+** TODO Skipping a line seems to break linums
 * Release process
 ** Update version number in Cargo.toml
 ** Update Nix flake and lock
diff --git a/shell.nix b/shell.nix
index f44c434..336ea1b 100644
--- a/shell.nix
+++ b/shell.nix
@@ -19,6 +19,7 @@ pkgs.mkShell {
     pkgs.gh
     pkgs.hyperfine
     pkgs.poppler_utils
+    pkgs.ripgrep
     pkgs.rustfmt
     pkgs.shellcheck
     pkgs.texlive.combined.scheme-full
diff --git a/src/indent.rs b/src/indent.rs
index 1f6f8a2..0aa983f 100644
--- a/src/indent.rs
+++ b/src/indent.rs
@@ -179,25 +179,28 @@ pub fn apply_indent(
     args: &Cli,
     indent_char: &str,
 ) -> String {
-    // Remove white space from the start of the line
-    let trimmed_line = line.trim_start();
+    let first_non_whitespace = line.chars().position(|c| !c.is_whitespace());
+
+    // If line is blank, return an empty line
+    if first_non_whitespace.is_none() {
+        return String::new();
+    }
+
+    // If line is correctly indented, return it directly
+    #[allow(clippy::cast_possible_wrap)]
+    let n_indent_chars = (indent.visual * args.tab as i8) as usize;
+    if first_non_whitespace == Some(n_indent_chars) {
+        return line.into();
+    }
 
-    // If the line is now empty, return a new empty String
-    if trimmed_line.is_empty() {
-        String::new()
     // Otherwise, allocate enough memory to fit line with the added
     // indentation and insert the appropriate string slices
-    } else {
-        // TODO can we check if the indent is already correct and do nothing?
-        #[allow(clippy::cast_possible_wrap)]
-        let n_indent_chars =
-            usize::try_from(indent.visual * args.tab as i8).unwrap();
-        let mut new_line =
-            String::with_capacity(trimmed_line.len() + n_indent_chars);
-        for idx in 0..n_indent_chars {
-            new_line.insert_str(idx, indent_char);
-        }
-        new_line.insert_str(n_indent_chars, trimmed_line);
-        new_line
+    let trimmed_line = line.trim_start();
+    let mut new_line =
+        String::with_capacity(trimmed_line.len() + n_indent_chars);
+    for idx in 0..n_indent_chars {
+        new_line.insert_str(idx, indent_char);
     }
+    new_line.insert_str(n_indent_chars, trimmed_line);
+    new_line
 }
diff --git a/tests/source/cam-thesis.cls b/tests/source/cam-thesis.cls
index 03034d6..86c4746 100644
--- a/tests/source/cam-thesis.cls
+++ b/tests/source/cam-thesis.cls
@@ -284,8 +284,6 @@ for the degree of Doctor of Philosophy%
 %%
 %% Chapter and section numbering
 %%
-% TODO: Check whether numbering up to the fourth level is okay. It is not
-% specified in the guidelines.
 \setcounter{secnumdepth}{3}
 \setcounter{tocdepth}{3}
 
diff --git a/tests/source/higher_categories_thesis.tex b/tests/source/higher_categories_thesis.tex
index 933723d..d5f666f 100644
--- a/tests/source/higher_categories_thesis.tex
+++ b/tests/source/higher_categories_thesis.tex
@@ -216,7 +216,6 @@
 \setlength\cellspacetoplimit{5pt} \setlength\cellspacebottomlimit{5pt}
 \newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}}
 
-%\usepackage{todonotes}
 \usepackage{ebproof}
 \usepackage{mathpartir}
 \usepackage{subcaption}
diff --git a/tests/target/cam-thesis.cls b/tests/target/cam-thesis.cls
index f1d16ab..d7e70f0 100644
--- a/tests/target/cam-thesis.cls
+++ b/tests/target/cam-thesis.cls
@@ -291,8 +291,6 @@
 %%
 %% Chapter and section numbering
 %%
-% TODO: Check whether numbering up to the fourth level is okay. It is not
-% specified in the guidelines.
 \setcounter{secnumdepth}{3}
 \setcounter{tocdepth}{3}
 
diff --git a/tests/target/higher_categories_thesis.tex b/tests/target/higher_categories_thesis.tex
index 12d013a..eab61c3 100644
--- a/tests/target/higher_categories_thesis.tex
+++ b/tests/target/higher_categories_thesis.tex
@@ -219,7 +219,6 @@
 \setlength\cellspacetoplimit{5pt} \setlength\cellspacebottomlimit{5pt}
 \newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}}
 
-%\usepackage{todonotes}
 \usepackage{ebproof}
 \usepackage{mathpartir}
 \usepackage{subcaption}