diff --git a/CHANGELOG.md b/CHANGELOG.md
index 626b6d6f..d9592ca7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 - Renamed `BASHUNIT_TESTS_ENV` to `BASHUNIT_LOAD_FILE`
 - Better handler runtime errors
 - Display failing tests after running the entire suite
+- Added defer expressions with `eval` when using standalone assertions
 
 ## [0.16.0](https://github.com/TypedDevs/bashunit/compare/0.15.0...0.16.0) - 2024-09-15
 
diff --git a/docs/standalone.md b/docs/standalone.md
index 52b44741..16f80791 100644
--- a/docs/standalone.md
+++ b/docs/standalone.md
@@ -43,3 +43,53 @@ The prefix `assert_` is optional.
 ```
 :::
 
+## Lazy evaluations
+
+You can evaluate the `exit_code` for your scripts using the command to call as raw-string instead of
+executing them with `$(...)` to avoid interrupting the CI when encountering a potential error (anything but `0`).
+
+::: code-group
+```bash [Example]
+./bashunit -a exit_code "1" "$PHPSTAN_PATH analyze \
+  --no-progress --level 8 \
+  --error-format raw ./"
+```
+```[Output]
+Testing.php:3:Method Testing::bar() has no return type specified.
+```
+:::
+
+This is useful to get control over the output of your "callable":
+
+::: code-group
+```bash [Example]
+OUTPUT=$(./bashunit -a exit_code "1" "$PHPSTAN_PATH analyze \
+  --no-progress --level 8 \
+  --error-format raw ./")
+./bashunit -a line_count 1 "$OUTPUT"
+```
+```[Output]
+# No output
+```
+:::
+
+### Full control over the stdout and stderr
+
+The stdout will be used for the callable result, while bashunit output will be on stderr.
+This way you can control the FD and redirect the output as you need.
+
+::: code-group
+```bash [Example]
+./bashunit -a exit_code "0" "$PHPSTAN_PATH analyze \
+  --no-progress --level 8 \
+  --error-format raw ./" 2> /tmp/error.log
+```
+```[Output]
+Testing.php:3:Method Testing::bar() has no return type specified.
+```
+```[/tmp/error.log]
+✗ Failed: Main::exec assert
+    Expected '0'
+    but got  '1'
+```
+:::
diff --git a/src/assert.sh b/src/assert.sh
index d9fdade3..07a54ba9 100755
--- a/src/assert.sh
+++ b/src/assert.sh
@@ -213,7 +213,7 @@ function assert_general_error() {
   local actual_exit_code=${3-"$?"}
   local expected_exit_code=1
 
-  if [[ $actual_exit_code -ne "$expected_exit_code" ]]; then
+  if [[ "$actual_exit_code" -ne "$expected_exit_code" ]]; then
     local label
     label="$(helper::normalize_test_function_name "${FUNCNAME[1]}")"
     state::add_assertions_failed
diff --git a/src/main.sh b/src/main.sh
index 9f7733d7..613d09b6 100644
--- a/src/main.sh
+++ b/src/main.sh
@@ -34,21 +34,76 @@ function main::exec_tests() {
 
 function main::exec_assert() {
   local original_assert_fn=$1
-  local assert_fn=$original_assert_fn
   local args=("${@:2}")
 
+  local assert_fn=$original_assert_fn
+
+  # Check if the function exists
   if ! type "$assert_fn" > /dev/null 2>&1; then
-    # try again using prefix `assert_`
     assert_fn="assert_$assert_fn"
     if ! type "$assert_fn" > /dev/null 2>&1; then
-      echo "Function $original_assert_fn does not exist."
+      echo "Function $original_assert_fn does not exist." 1>&2
       exit 127
     fi
   fi
 
-  "$assert_fn" "${args[@]}"
+  # Get the last argument safely by calculating the array length
+  local last_index=$((${#args[@]} - 1))
+  local last_arg="${args[$last_index]}"
+  local output=""
+  local inner_exit_code=0
+  local bashunit_exit_code=0
+
+  # Handle different assert_* functions
+  case "$assert_fn" in
+    assert_exit_code)
+      output=$(main::handle_assert_exit_code "$last_arg")
+      inner_exit_code=$?
+      # Remove the last argument and append the exit code
+      args=("${args[@]:0:last_index}")
+      args+=("$inner_exit_code")
+      ;;
+    *)
+      # Add more cases here for other assert_* handlers if needed
+      ;;
+  esac
+
+  if [[ -n "$output" ]]; then
+    echo "$output" 1>&1
+    assert_fn="assert_same"
+  fi
+
+  # Run the assertion function and write into stderr
+  "$assert_fn" "${args[@]}" 1>&2
+  bashunit_exit_code=$?
 
   if [[ "$(state::get_tests_failed)" -gt 0 ]] || [[ "$(state::get_assertions_failed)" -gt 0 ]]; then
-      exit 1
+    return 1
+  fi
+
+  return "$bashunit_exit_code"
+}
+
+function main::handle_assert_exit_code() {
+  local cmd="$1"
+  local output
+  local inner_exit_code=0
+
+  if [[ $(command -v "${cmd%% *}") ]]; then
+    output=$(eval "$cmd" 2>&1 || echo "inner_exit_code:$?")
+    local last_line
+    last_line=$(echo "$output" | tail -n 1)
+    if echo "$last_line" | grep -q 'inner_exit_code:[0-9]*'; then
+      inner_exit_code=$(echo "$last_line" | grep -o 'inner_exit_code:[0-9]*' | cut -d':' -f2)
+      if ! [[ $inner_exit_code =~ ^[0-9]+$ ]]; then
+        inner_exit_code=1
+      fi
+      output=$(echo "$output" | sed '$d')
+    fi
+    echo "$output"
+    return "$inner_exit_code"
+  else
+    echo "Command not found: $cmd" 1>&2
+    return 127
   fi
 }
diff --git a/tests/acceptance/bashunit_direct_fn_call_test.sh b/tests/acceptance/bashunit_direct_fn_call_test.sh
index 8fe89796..4f99f7aa 100644
--- a/tests/acceptance/bashunit_direct_fn_call_test.sh
+++ b/tests/acceptance/bashunit_direct_fn_call_test.sh
@@ -74,11 +74,73 @@ function test_bashunit_direct_fn_call_failure() {
   local expected="foo"
   local actual="bar"
 
-  assert_match_snapshot "$(./bashunit -a assert_same --env "$TEST_ENV_FILE" "$expected" $actual)"
+  assert_match_snapshot "$(./bashunit -a assert_same --env "$TEST_ENV_FILE" "$expected" $actual 2>&1)"
   assert_general_error "$(./bashunit -a assert_same --env "$TEST_ENV_FILE" "$expected" $actual)"
 }
 
 function test_bashunit_direct_fn_call_non_existing_fn() {
-  assert_match_snapshot "$(./bashunit -a non_existing_fn --env "$TEST_ENV_FILE")"
+  assert_match_snapshot "$(./bashunit -a non_existing_fn --env "$TEST_ENV_FILE" 2>&1)"
   assert_command_not_found "$(./bashunit -a non_existing_fn --env "$TEST_ENV_FILE")"
 }
+
+# shellcheck disable=SC2155
+function test_bashunit_assert_exit_code_successful_with_inner_func() {
+  local temp=$(mktemp)
+  # shellcheck disable=SC2116
+  local output="$(./bashunit -a exit_code "0" "$(echo "unknown command")" 2> "$temp")"
+
+  assert_empty "$output"
+  assert_same "Command not found: unknown command" "$(cat "$temp")"
+
+  rm "$temp"
+}
+
+# shellcheck disable=SC2155
+function test_bashunit_assert_exit_code_error_with_inner_func() {
+  local temp=$(mktemp)
+  # shellcheck disable=SC2116
+  local output="$(./bashunit -a exit_code "1" "$(echo "unknown command")" 2> "$temp")"
+
+  assert_empty "$output"
+
+  assert_contains\
+    "$(console_results::print_failed_test "Main::exec assert" "0" "to be" "1")"\
+    "$(cat "$temp")"
+
+  rm "$temp"
+}
+
+function test_bashunit_assert_exit_code_str_successful_code() {
+  ./bashunit -a exit_code "0" "./bashunit -a same 1 1"
+  assert_successful_code
+}
+
+function test_bashunit_assert_exit_code_str_general_error() {
+  ./bashunit -a exit_code "1" "./bashunit -a same 1 2"
+  assert_successful_code
+}
+
+# shellcheck disable=SC2155
+function test_bashunit_assert_exit_code_str_successful_but_exit_code_error() {
+  local temp=$(mktemp)
+  local output="$(./bashunit -a exit_code "1" "echo something to stdout" 2> "$temp")"
+
+  assert_same "something to stdout" "$output"
+
+  assert_contains\
+    "$(console_results::print_failed_test "Main::exec assert" "1" "but got " "0")"\
+    "$(cat "$temp")"
+
+  rm "$temp"
+}
+
+# shellcheck disable=SC2155
+function test_bashunit_assert_exit_code_str_successful_and_exit_code_ok() {
+  local temp=$(mktemp)
+  local output="$(./bashunit -a exit_code "0" "echo something to stdout" 2> "$temp")"
+
+  assert_same "something to stdout" "$output"
+  assert_empty "$(cat "$temp")"
+
+  rm "$temp"
+}