diff --git a/CHANGELOG.md b/CHANGELOG.md
index 77ccd24c..66cdfec4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### Fixed
 - Custom assertions now display the correct test function name in failure messages
+- Data providers now work when `set_up_before_script` changes directory
 
 ## [0.28.0](https://github.com/TypedDevs/bashunit/compare/0.27.0...0.28.0) - 2025-12-01
 
diff --git a/bashunit b/bashunit
index 05a4a931..0b0fd379 100755
--- a/bashunit
+++ b/bashunit
@@ -34,6 +34,10 @@ declare -r BASHUNIT_VERSION="0.28.0"
 declare -r BASHUNIT_ROOT_DIR="$(dirname "${BASH_SOURCE[0]}")"
 export BASHUNIT_ROOT_DIR
 
+# Capture working directory at startup (before any test changes it)
+declare -r BASHUNIT_WORKING_DIR="$PWD"
+export BASHUNIT_WORKING_DIR
+
 source "$BASHUNIT_ROOT_DIR/src/dev/debug.sh"
 source "$BASHUNIT_ROOT_DIR/src/check_os.sh"
 source "$BASHUNIT_ROOT_DIR/src/str.sh"
diff --git a/src/helpers.sh b/src/helpers.sh
index e8b23fdb..0507ec4b 100755
--- a/src/helpers.sh
+++ b/src/helpers.sh
@@ -130,6 +130,11 @@ function helper::decode_base64() {
 function helper::check_duplicate_functions() {
   local script="$1"
 
+  # Handle directory changes in set_up_before_script (issue #529)
+  if [[ ! -f "$script" && -n "${BASHUNIT_WORKING_DIR:-}" ]]; then
+    script="$BASHUNIT_WORKING_DIR/$script"
+  fi
+
   local filtered_lines
   filtered_lines=$(grep -E '^[[:space:]]*(function[[:space:]]+)?test[a-zA-Z_][a-zA-Z0-9_]*\s*\(\)\s*\{' "$script")
 
@@ -244,6 +249,12 @@ function helper::get_provider_data() {
   local function_name="$1"
   local script="$2"
 
+  # Handle directory changes in set_up_before_script (issue #529)
+  # If relative path doesn't exist, try with BASHUNIT_WORKING_DIR
+  if [[ ! -f "$script" && -n "${BASHUNIT_WORKING_DIR:-}" ]]; then
+    script="$BASHUNIT_WORKING_DIR/$script"
+  fi
+
   if [[ ! -f "$script" ]]; then
     return
   fi
diff --git a/tests/functional/provider_with_cd_test.sh b/tests/functional/provider_with_cd_test.sh
new file mode 100644
index 00000000..d6604c17
--- /dev/null
+++ b/tests/functional/provider_with_cd_test.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Regression test for https://github.com/TypedDevs/bashunit/issues/529
+# Data providers should work even when set_up_before_script changes directory
+
+function set_up_before_script() {
+  cd "$(temp_dir)" || return 1
+}
+
+# @data_provider provide_data
+function test_data_provider_works_after_cd_in_set_up_before_script() {
+  local value="$1"
+
+  assert_equals "expected_value" "$value"
+}
+
+function provide_data() {
+  echo "expected_value"
+}