diff --git a/sop-java/src/test/java/sop/util/MicAlgTest.java b/sop-java/src/test/java/sop/util/MicAlgTest.java
new file mode 100644
index 00000000..f720c85b
--- /dev/null
+++ b/sop-java/src/test/java/sop/util/MicAlgTest.java
@@ -0,0 +1,53 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import sop.MicAlg;
+
+public class MicAlgTest {
+
+    @Test
+    public void constructorNullArgThrows() {
+        assertThrows(IllegalArgumentException.class, () -> new MicAlg(null));
+    }
+
+    @Test
+    public void emptyMicAlgIsEmptyString() {
+        MicAlg empty = MicAlg.empty();
+        assertNotNull(empty.getMicAlg());
+        assertTrue(empty.getMicAlg().isEmpty());
+    }
+
+    @Test
+    public void fromInvalidAlgorithmIdThrows() {
+        assertThrows(IllegalArgumentException.class, () -> MicAlg.fromHashAlgorithmId(-1));
+    }
+
+    @Test
+    public void fromHashAlgorithmIdsKnownAlgsMatch() {
+        Map<Integer, String> knownAlgorithmMicalgs = new HashMap<>();
+        knownAlgorithmMicalgs.put(1, "pgp-md5");
+        knownAlgorithmMicalgs.put(2, "pgp-sha1");
+        knownAlgorithmMicalgs.put(3, "pgp-ripemd160");
+        knownAlgorithmMicalgs.put(8, "pgp-sha256");
+        knownAlgorithmMicalgs.put(9, "pgp-sha384");
+        knownAlgorithmMicalgs.put(10, "pgp-sha512");
+        knownAlgorithmMicalgs.put(11, "pgp-sha224");
+
+        for (Integer id : knownAlgorithmMicalgs.keySet()) {
+            MicAlg micAlg = MicAlg.fromHashAlgorithmId(id);
+            assertEquals(knownAlgorithmMicalgs.get(id), micAlg.getMicAlg());
+        }
+    }
+}