diff --git a/CHANGELOG.md b/CHANGELOG.md
index 04f7b5ff..a1815da8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@
 - Syntax highlighting for Python files using uv as script runner in shebang #3689 (@janlarres)
 
 ## Bugfixes
+- Report `BAT_CONFIG_DIR` in `bat --diagnostic`, so bug reports show a config directory that overrides `$XDG_CONFIG_HOME`. See #4068 (@ump45nose)
 - Fix `bat` hanging forever on JavaScript (and Svelte) code where an expression is followed by a block comment, e.g. `a /* x */`. Closes #4080, see #4091 (@NavpreetSSidhu)
 - Fix the first line of UTF-16BE input swallowing the second line, which broke line numbers, `--line-range` and highlighting, see #XXXX (@cindykrafft)
 - Exit quietly with status 0 instead of panicking when stdout is closed early (broken pipe) on auxiliary output paths such as `--completion`, `--config-file`, `--diagnostic`, `--generate-config-file`, `--set-terminal-title` and `cache --build`/`--clear`, matching the main output path since #232, closes #4034, see #4035 (@Mathjk)
diff --git a/src/bin/bat/main.rs b/src/bin/bat/main.rs
index 359219be..9019e9d6 100644
--- a/src/bin/bat/main.rs
+++ b/src/bin/bat/main.rs
@@ -333,6 +333,7 @@ fn invoke_bugreport(app: &App, cache_dir: &Path) -> Result<()> {
         .info(CommandLine::default())
         .info(EnvironmentVariables::list(&[
             "BAT_CACHE_PATH",
+            "BAT_CONFIG_DIR",
             "BAT_CONFIG_PATH",
             "BAT_OPTS",
             "BAT_PAGER",
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index a418ce70..1d252015 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -1755,6 +1755,7 @@ fn diagnostic_sanity_check() {
         .success()
         .stdout(predicate::str::contains("BAT_PAGER="))
         .stdout(predicate::str::contains("BAT_WIDTH="))
+        .stdout(predicate::str::contains("BAT_CONFIG_DIR="))
         .stderr("");
 }