diff --git a/.github/workflows/testo.yml b/.github/workflows/testo.yml
index 74f3645..d05ebb4 100644
--- a/.github/workflows/testo.yml
+++ b/.github/workflows/testo.yml
@@ -81,7 +81,7 @@ on:
         type: string
       testo-additional-args:
         description: Additional Testo arguments, separated by whitespace.
-        default: "--log-junit=junit.xml"
+        default: ""
         required: false
         type: string
       testo-configuration:
@@ -104,6 +104,11 @@ on:
         default:
         required: false
         type: string
+      testo-junit-file:
+        description: JUnit report file, passed with `--log-junit` and uploaded to Codecov as test results; empty disables it.
+        default: junit.xml
+        required: false
+        type: string
       testo-path:
         description: Path to the Testo executable.
         default: vendor/bin/testo
@@ -191,6 +196,7 @@ jobs:
           exclude-group: ${{ inputs.testo-exclude-group }}
           filter: ${{ inputs.testo-filter }}
           group: ${{ inputs.testo-group }}
+          junit-file: ${{ inputs.testo-junit-file }}
           path: ${{ inputs.testo-path }}
           suite: ${{ inputs.testo-suite }}
           type: ${{ inputs.testo-type }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dda9fb1..399954b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## v3.0.2 Under development
 
+- feat(testo): add junit-file input for JUnit report and update additional args handling.
+
 ## v3.0.1 October 26, 2026
 
 - ci(actions): add the reusable `testo.yml` workflow and the `testo` composite action to run Testo suites with coverage and Codecov uploads.
diff --git a/actions/phpunit/action.yml b/actions/phpunit/action.yml
index e675985..628206f 100644
--- a/actions/phpunit/action.yml
+++ b/actions/phpunit/action.yml
@@ -87,8 +87,9 @@ runs:
           PHPUNIT_CMD="$PHPUNIT_CMD $DEBUG_INPUT"
         fi
 
+        # Line breaks are replaced with spaces so the command stays a single `GITHUB_OUTPUT` line.
         if [ -n "$ADDITIONAL_ARGS" ]; then
-          PHPUNIT_CMD="$PHPUNIT_CMD $ADDITIONAL_ARGS"
+          PHPUNIT_CMD="$PHPUNIT_CMD ${ADDITIONAL_ARGS//[$'\r\n']/ }"
         fi
 
         echo "command=$PHPUNIT_CMD" >> "$GITHUB_OUTPUT"
@@ -116,7 +117,12 @@ runs:
         report_type: test_results
 
     - name: Upload coverage to Codecov.
-      if: ${{ !cancelled() && inputs.coverage-driver != 'none' }}
+      if: >-
+        ${{
+        !cancelled()
+        && inputs.coverage-driver != ''
+        && inputs.coverage-driver != 'none'
+        }}
       uses: codecov/codecov-action@0fb7174895f61a3b6b78fc075e0cd60383518dac # v5.5.5
       with:
         token: ${{ inputs.coverage-token }}
diff --git a/actions/testo/action.yml b/actions/testo/action.yml
index da92ed7..7d55bf6 100644
--- a/actions/testo/action.yml
+++ b/actions/testo/action.yml
@@ -5,7 +5,7 @@ description: Run Testo tests with coverage and configurable options.
 inputs:
   additional-args:
     description: Additional Testo arguments, separated by whitespace.
-    default: "--log-junit=junit.xml"
+    default: ""
     required: false
   configuration:
     description: Testo configuration file, passed with `--config`.
@@ -39,6 +39,10 @@ inputs:
     description: Group to run, passed with `--group`.
     default: ""
     required: false
+  junit-file:
+    description: JUnit report file, passed with `--log-junit` and uploaded to Codecov as test results; empty disables it.
+    default: junit.xml
+    required: false
   path:
     description: Path to the Testo executable.
     default: vendor/bin/testo
@@ -67,6 +71,7 @@ runs:
         EXCLUDE_GROUP_INPUT: ${{ inputs.exclude-group }}
         FILTER_INPUT: ${{ inputs.filter }}
         GROUP_INPUT: ${{ inputs.group }}
+        JUNIT_FILE: ${{ inputs.junit-file }}
         PATH_INPUT: ${{ inputs.path }}
         SUITE_INPUT: ${{ inputs.suite }}
         TYPE_INPUT: ${{ inputs.type }}
@@ -85,6 +90,7 @@ runs:
           args+=("--coverage-$COVERAGE_FORMAT=$COVERAGE_FILE")
         fi
 
+        add_param "--log-junit" "$JUNIT_FILE"
         add_param "--config" "$CONFIG_INPUT"
         add_param "--suite" "$SUITE_INPUT"
         add_param "--filter" "$FILTER_INPUT"
@@ -97,8 +103,9 @@ runs:
         add_param "--type" "$TYPE_INPUT"
 
         # Additional arguments are whitespace-separated; each word is passed as one argument.
+        # Line breaks are replaced with spaces so multi-line values split like the Windows step.
         if [ -n "$ADDITIONAL_ARGS" ]; then
-          read -r -a extra <<< "$ADDITIONAL_ARGS"
+          read -r -a extra <<< "${ADDITIONAL_ARGS//[$'\r\n']/ }"
 
           if [ "${#extra[@]}" -gt 0 ]; then
             args+=("${extra[@]}")
@@ -123,6 +130,7 @@ runs:
         EXCLUDE_GROUP_INPUT: ${{ inputs.exclude-group }}
         FILTER_INPUT: ${{ inputs.filter }}
         GROUP_INPUT: ${{ inputs.group }}
+        JUNIT_FILE: ${{ inputs.junit-file }}
         PATH_INPUT: ${{ inputs.path }}
         SUITE_INPUT: ${{ inputs.suite }}
         TYPE_INPUT: ${{ inputs.type }}
@@ -139,6 +147,7 @@ runs:
           $testoArgs += "--coverage-$($env:COVERAGE_FORMAT)=$($env:COVERAGE_FILE)"
         }
 
+        Add-Param '--log-junit' $env:JUNIT_FILE
         Add-Param '--config' $env:CONFIG_INPUT
         Add-Param '--suite' $env:SUITE_INPUT
         Add-Param '--filter' $env:FILTER_INPUT
@@ -164,14 +173,20 @@ runs:
         }
 
     - name: Upload test results to Codecov.
-      if: ${{ !cancelled() }}
+      if: ${{ !cancelled() && inputs.junit-file != '' }}
       uses: codecov/codecov-action@0fb7174895f61a3b6b78fc075e0cd60383518dac # v5.5.5
       with:
         token: ${{ inputs.coverage-token }}
+        files: ./${{ inputs.junit-file }}
         report_type: test_results
 
     - name: Upload coverage to Codecov.
-      if: ${{ !cancelled() && inputs.coverage-driver != 'none' }}
+      if: >-
+        ${{
+        !cancelled()
+        && inputs.coverage-driver != ''
+        && inputs.coverage-driver != 'none'
+        }}
       uses: codecov/codecov-action@0fb7174895f61a3b6b78fc075e0cd60383518dac # v5.5.5
       with:
         token: ${{ inputs.coverage-token }}