diff --git a/CMakeLists.txt b/CMakeLists.txt
index 69cac3ec..c00e246b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -604,6 +604,7 @@ if(WITH_TESTS)
     dwarfs_test
     entry_test
     file_access_test
+    fragment_category_test
     incompressible_categorizer_test
     metadata_requirements_test
     pcm_sample_transformer_test
diff --git a/test/fragment_category_test.cpp b/test/fragment_category_test.cpp
new file mode 100644
index 00000000..d82433b5
--- /dev/null
+++ b/test/fragment_category_test.cpp
@@ -0,0 +1,119 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/**
+ * \author     Marcus Holland-Moritz (github@mhxnet.de)
+ * \copyright  Copyright (c) Marcus Holland-Moritz
+ *
+ * This file is part of dwarfs.
+ *
+ * dwarfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dwarfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dwarfs.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <algorithm>
+#include <sstream>
+#include <unordered_set>
+#include <vector>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <fmt/format.h>
+
+#include "dwarfs/fragment_category.h"
+
+using namespace dwarfs;
+
+TEST(fragment_category_test, basic) {
+  fragment_category c;
+
+  EXPECT_TRUE(c.empty());
+  EXPECT_FALSE(c);
+  EXPECT_FALSE(c.has_subcategory());
+
+  {
+    std::ostringstream oss;
+    oss << c;
+
+    EXPECT_EQ("uninitialized", oss.str());
+  }
+
+  EXPECT_EQ("uninitialized", fmt::format("{}", c));
+
+  c = fragment_category::value_type{42};
+
+  EXPECT_FALSE(c.empty());
+  EXPECT_TRUE(c);
+  EXPECT_FALSE(c.has_subcategory());
+  EXPECT_EQ(42, c.value());
+
+  {
+    std::ostringstream oss;
+    oss << c;
+
+    EXPECT_EQ("42", oss.str());
+  }
+
+  EXPECT_EQ("42", fmt::format("{}", c));
+
+  c.set_subcategory(43);
+
+  EXPECT_FALSE(c.empty());
+  EXPECT_TRUE(c);
+  EXPECT_TRUE(c.has_subcategory());
+  EXPECT_EQ(42, c.value());
+  EXPECT_EQ(43, c.subcategory());
+
+  {
+    std::ostringstream oss;
+    oss << c;
+
+    EXPECT_EQ("42.43", oss.str());
+  }
+
+  EXPECT_EQ("42.43", fmt::format("{}", c));
+
+  c.clear();
+
+  EXPECT_TRUE(c.empty());
+  EXPECT_FALSE(c);
+  EXPECT_FALSE(c.has_subcategory());
+}
+
+TEST(fragment_category_test, hash_table) {
+  std::unordered_set<fragment_category> s;
+
+  s.emplace(1);
+  s.emplace(2, 3);
+  s.emplace(4, 5);
+
+  EXPECT_EQ(3, s.size());
+  EXPECT_EQ(1, s.count(fragment_category{1}));
+  EXPECT_EQ(1, s.count(fragment_category{2, 3}));
+  EXPECT_EQ(1, s.count(fragment_category{4, 5}));
+}
+
+TEST(fragment_category_test, sortable) {
+  std::vector<fragment_category> v;
+
+  v.emplace_back(4, 5);
+  v.emplace_back(1);
+  v.emplace_back(2, 3);
+  v.emplace_back(2);
+
+  std::sort(v.begin(), v.end());
+
+  EXPECT_EQ(fragment_category(1), v[0]);
+  EXPECT_EQ(fragment_category(2, 3), v[1]);
+  EXPECT_EQ(fragment_category(2), v[2]);
+  EXPECT_EQ(fragment_category(4, 5), v[3]);
+}