diff --git a/tests/testthat/test-return_linter.R b/tests/testthat/test-return_linter.R
index b05b3abd3..58a5d1cf9 100644
--- a/tests/testthat/test-return_linter.R
+++ b/tests/testthat/test-return_linter.R
@@ -691,6 +691,20 @@ test_that("except_regex= argument works", {
     list(rex::rex("All functions must have an explicit return()."), line_number = 5L),
     linter
   )
+
+  # capture group doesn't cause issues, #2678
+  expect_lint(
+    trim_some("
+      TestFun <- function() {
+        non_return()
+      }
+      AssertFun <- function() {
+        non_return()
+      }
+    "),
+    NULL,
+    return_linter(return_style = "explicit", except_regex = "^(Test|Assert)")
+  )
 })
 
 test_that("except= and except_regex= combination works", {
diff --git a/tests/testthat/test-todo_comment_linter.R b/tests/testthat/test-todo_comment_linter.R
index 103f9c8fc..b7793d1d8 100644
--- a/tests/testthat/test-todo_comment_linter.R
+++ b/tests/testthat/test-todo_comment_linter.R
@@ -57,4 +57,11 @@ test_that("except_regex= excludes valid TODO", {
     NULL,
     todo_comment_linter(except_regex = c("TODO\\(#[0-9]+\\):", "fixme\\(#[0-9]+\\):"))
   )
+
+  # ignore captured groups
+  expect_lint(
+    "# TODO(a)",
+    NULL,
+    todo_comment_linter(except_regex = "TODO\\((a|abc)\\)")
+  )
 })
diff --git a/tests/testthat/test-unreachable_code_linter.R b/tests/testthat/test-unreachable_code_linter.R
index 167909d50..b54d3b11e 100644
--- a/tests/testthat/test-unreachable_code_linter.R
+++ b/tests/testthat/test-unreachable_code_linter.R
@@ -687,6 +687,19 @@ test_that("allow_comment_regex= works", {
     NULL,
     linter_x1x2
   )
+
+  # might contain capture groups, #2678
+  expect_lint(
+    trim_some("
+      function() {
+        stop('a')
+        # a
+        # ab
+      }
+    "),
+    NULL,
+    unreachable_code_linter(allow_comment_regex = "#\\s*(a|ab|abc)")
+  )
 })
 
 test_that("allow_comment_regex= obeys covr's custom exclusion when set", {