diff --git a/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RuleSource.java b/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RuleSource.java
index 0e7db03..c7b2dc1 100644
--- a/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RuleSource.java
+++ b/builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/RuleSource.java
@@ -32,5 +32,5 @@ package net.kemitix.checkstyle.ruleset.builder;
 public enum RuleSource {
 
     CHECKSTYLE,
-    SEVNTU;
+    SEVNTU,
 }
diff --git a/builder/src/test/java/net/kemitix/checkstyle/ruleset/builder/RuleSourceTest.java b/builder/src/test/java/net/kemitix/checkstyle/ruleset/builder/RuleSourceTest.java
new file mode 100644
index 0000000..3cf5562
--- /dev/null
+++ b/builder/src/test/java/net/kemitix/checkstyle/ruleset/builder/RuleSourceTest.java
@@ -0,0 +1,33 @@
+package net.kemitix.checkstyle.ruleset.builder;
+
+import lombok.val;
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link RuleSource}.
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
+ */
+public class RuleSourceTest {
+
+    @Test
+    public void valueOf() throws Exception {
+        assertThat(RuleSource.valueOf("CHECKSTYLE")).isEqualTo(RuleSource.CHECKSTYLE);
+        assertThat(RuleSource.valueOf("SEVNTU")).isEqualTo(RuleSource.SEVNTU);
+    }
+
+    @Test
+    public void values() throws Exception {
+        //given
+        val expected = Arrays.asList("CHECKSTYLE", "SEVNTU");
+        //when
+        val values = Arrays.stream(RuleSource.values())
+                           .map(RuleSource::toString);
+        //then
+        assertThat(values).containsExactlyElementsOf(expected);
+    }
+}