diff --git a/.travis.yml b/.travis.yml
index 03071a4..2a5ff5e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,11 @@
 sudo: false
 language: php
+addons:
+  apt:
+    packages:
+      - locales
+      - language-pack-de
+      - language-pack-fr
 cache:
   directories:
     - $HOME/.composer/cache
diff --git a/Makefile b/Makefile
index f3065b7..1d8a73a 100644
--- a/Makefile
+++ b/Makefile
@@ -124,8 +124,20 @@ test:
 	@echo "-------"
 	@echo "PHPUNIT"
 	@echo "-------"
-	@mkdir -p sandbox
-	@$(BIN)/phpunit tests
+	@mkdir -p sandbox coverage
+	@$(BIN)/phpunit --coverage-php coverage/main.cov --testsuite unit-tests
+
+locale_test_%:
+	@UT_LOCALE=$*.utf8 \
+		$(BIN)/phpunit \
+		--coverage-php coverage/$(firstword $(subst _, ,$*)).cov \
+		--bootstrap tests/languages/bootstrap.php \
+		--testsuite language-$(firstword $(subst _, ,$*))
+
+all_tests: test locale_test_de_DE locale_test_en_US locale_test_fr_FR
+	@$(BIN)/phpcov merge --html coverage coverage
+	@# --text doesn't work with phpunit 4.* (v5 requires PHP 5.6)
+	@#$(BIN)/phpcov merge --text coverage/txt coverage
 
 ##
 # Custom release archive generation
diff --git a/composer.json b/composer.json
index b82acee..70b87bb 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,8 @@
         "phpmd/phpmd" : "@stable",
         "phpunit/phpunit": "4.8.*",
         "sebastian/phpcpd": "*",
-        "squizlabs/php_codesniffer": "2.*"
+        "squizlabs/php_codesniffer": "2.*",
+        "phpunit/phpcov": "*"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml b/phpunit.xml
index d6e01c3..8b66e6c 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -3,13 +3,25 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.5/phpunit.xsd"
     colors="true">
+  <testsuites>
+    <testsuite name="unit-tests">
+      <directory>tests</directory>
+      <exclude>tests/languages</exclude>
+    </testsuite>
+    <testsuite name="language-de">
+      <directory>tests/languages/de</directory>
+    </testsuite>
+    <testsuite name="language-en">
+      <directory>tests/languages/en</directory>
+    </testsuite>
+    <testsuite name="language-fr">
+      <directory>tests/languages/fr</directory>
+    </testsuite>
+  </testsuites>
+
   <filter>
     <whitelist addUncoveredFilesFromWhitelist="true">
       <directory suffix=".php">application</directory>
     </whitelist>
   </filter>
-  <logging>
-    <log type="coverage-html" target="coverage" lowUpperBound="30" highLowerBound="80"/>
-    <log type="coverage-text" target="php://stdout" showUncoveredFiles="true"/>
-  </logging>
 </phpunit>