diff --git a/libsolutil/FixedHash.h b/libsolutil/FixedHash.h
index f2c2cbcc5..dffeb7a17 100644
--- a/libsolutil/FixedHash.h
+++ b/libsolutil/FixedHash.h
@@ -48,6 +48,7 @@ public:
 
 	/// The size of the container.
 	enum { size = N };
+	static_assert(N != 0);
 
 	/// Method to convert from a string.
 	enum ConstructFromStringType { FromHex, FromBinary };
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index caa587415..f7adf16a9 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -29,6 +29,7 @@ detect_stray_source_files("${contracts_sources}" "contracts/")
 set(libsolutil_sources
     libsolutil/Checksum.cpp
     libsolutil/CommonData.cpp
+    libsolutil/FixedHash.cpp
     libsolutil/IndentedWriter.cpp
     libsolutil/IpfsHash.cpp
     libsolutil/IterateReplacing.cpp
diff --git a/test/libsolutil/FixedHash.cpp b/test/libsolutil/FixedHash.cpp
new file mode 100644
index 000000000..4efe0a9e1
--- /dev/null
+++ b/test/libsolutil/FixedHash.cpp
@@ -0,0 +1,272 @@
+/*
+	This file is part of solidity.
+
+	solidity 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.
+
+	solidity 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 solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Unit tests for FixedHash.
+ */
+
+#include <libsolutil/FixedHash.h>
+
+#include <boost/test/unit_test.hpp>
+
+#include <cstdint>
+#include <sstream>
+
+using namespace std;
+
+namespace solidity::util::test
+{
+
+static_assert(std::is_same<h160, FixedHash<20>>());
+static_assert(std::is_same<h256, FixedHash<32>>());
+
+BOOST_AUTO_TEST_SUITE(FixedHashTest)
+
+BOOST_AUTO_TEST_CASE(default_constructor)
+{
+	BOOST_CHECK_EQUAL(
+		FixedHash<1>{}.hex(),
+		"00"
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<1>{}.size,
+		1
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<8>{}.hex(),
+		"0000000000000000"
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<8>{}.size,
+		8
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<20>{}.hex(),
+		"0000000000000000000000000000000000000000"
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<20>{}.size,
+		20
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<32>{}.hex(),
+		"0000000000000000000000000000000000000000000000000000000000000000"
+	);
+	BOOST_CHECK_EQUAL(
+		FixedHash<32>{}.size,
+		32
+	);
+}
+
+BOOST_AUTO_TEST_CASE(bytes_constructor)
+{
+	FixedHash<8> a(bytes{});
+	BOOST_CHECK_EQUAL(a.size, 8);
+	BOOST_CHECK_EQUAL(a.hex(), "0000000000000000");
+
+	FixedHash<8> b(bytes{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88});
+	BOOST_CHECK_EQUAL(b.size, 8);
+	BOOST_CHECK_EQUAL(b.hex(), "1122334455667788");
+
+	// TODO: short input, this should fail
+	FixedHash<8> c(bytes{0x11, 0x22, 0x33, 0x44, 0x55, 0x66});
+	BOOST_CHECK_EQUAL(c.size, 8);
+	BOOST_CHECK_EQUAL(c.hex(), "0000000000000000");
+
+	// TODO: oversized input, this should fail
+	FixedHash<8> d(bytes{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99});
+	BOOST_CHECK_EQUAL(d.size, 8);
+	BOOST_CHECK_EQUAL(d.hex(), "0000000000000000");
+}
+
+// TODO: add FixedHash(bytesConstRef) constructor
+
+BOOST_AUTO_TEST_CASE(string_constructor_fromhex)
+{
+	// TODO: this tests the default settings ConstructFromStringType::fromHex, ConstructFromHashType::FailIfDifferent
+	//       should test other options too
+
+	FixedHash<8> a("");
+	BOOST_CHECK_EQUAL(a.size, 8);
+	BOOST_CHECK_EQUAL(a.hex(), "0000000000000000");
+
+	FixedHash<8> b("1122334455667788");
+	BOOST_CHECK_EQUAL(b.size, 8);
+	BOOST_CHECK_EQUAL(b.hex(), "1122334455667788");
+
+	FixedHash<8> c("0x1122334455667788");
+	BOOST_CHECK_EQUAL(c.size, 8);
+	BOOST_CHECK_EQUAL(c.hex(), "1122334455667788");
+
+	// TODO: short input, this should fail
+	FixedHash<8> d("112233445566");
+	BOOST_CHECK_EQUAL(d.size, 8);
+	BOOST_CHECK_EQUAL(d.hex(), "0000000000000000");
+
+	// TODO: oversized input, this should fail
+	FixedHash<8> e("112233445566778899");
+	BOOST_CHECK_EQUAL(e.size, 8);
+	BOOST_CHECK_EQUAL(e.hex(), "0000000000000000");
+}
+
+BOOST_AUTO_TEST_CASE(string_constructor_frombytes)
+{
+
+	FixedHash<8> b("", FixedHash<8>::FromBinary);
+	BOOST_CHECK_EQUAL(b.size, 8);
+	BOOST_CHECK_EQUAL(b.hex(), "0000000000000000");
+
+	FixedHash<8> c("abcdefgh", FixedHash<8>::FromBinary);
+	BOOST_CHECK_EQUAL(c.size, 8);
+	BOOST_CHECK_EQUAL(c.hex(), "6162636465666768");
+
+	// TODO: short input, this should fail
+	FixedHash<8> d("abcdefg", FixedHash<8>::FromBinary);
+	BOOST_CHECK_EQUAL(d.size, 8);
+	BOOST_CHECK_EQUAL(d.hex(), "0000000000000000");
+
+	// TODO: oversized input, this should fail
+	FixedHash<8> e("abcdefghi", FixedHash<8>::FromBinary);
+	BOOST_CHECK_EQUAL(e.size, 8);
+	BOOST_CHECK_EQUAL(e.hex(), "0000000000000000");
+}
+
+BOOST_AUTO_TEST_CASE(converting_constructor)
+{
+	// Truncation
+	FixedHash<8> a = FixedHash<8>(FixedHash<12>("112233445566778899001122"));
+	BOOST_CHECK_EQUAL(a.size, 8);
+	BOOST_CHECK_EQUAL(a.hex(), "1122334455667788");
+
+	// Left-aligned extension
+	FixedHash<12> b = FixedHash<12>(FixedHash<8>("1122334455667788"), FixedHash<12>::AlignLeft);
+	BOOST_CHECK_EQUAL(b.size, 12);
+	BOOST_CHECK_EQUAL(b.hex(), "112233445566778800000000");
+
+	// Right-aligned extension
+	FixedHash<12> c = FixedHash<12>(FixedHash<8>("1122334455667788"), FixedHash<12>::AlignRight);
+	BOOST_CHECK_EQUAL(c.size, 12);
+	BOOST_CHECK_EQUAL(c.hex(), "000000001122334455667788");
+
+	// Default setting
+	FixedHash<12> d = FixedHash<12>(FixedHash<8>("1122334455667788"));
+	BOOST_CHECK_EQUAL(d, b);
+
+	// FailIfDifferent setting
+	// TODO: Shouldn't this throw?
+	FixedHash<12> e = FixedHash<12>(FixedHash<8>("1122334455667788"), FixedHash<12>::FailIfDifferent);
+	BOOST_CHECK_EQUAL(e, b);
+}
+
+BOOST_AUTO_TEST_CASE(arith_constructor)
+{
+	FixedHash<20> a(u160(0x1234));
+	BOOST_CHECK_EQUAL(
+		a.hex(),
+		"0000000000000000000000000000000000001234"
+	);
+
+	FixedHash<32> b(u256(0x12340000));
+	BOOST_CHECK_EQUAL(
+		b.hex(),
+		"0000000000000000000000000000000000000000000000000000000012340000"
+	);
+
+	// NOTE: size-mismatched constructor is not available
+}
+
+BOOST_AUTO_TEST_CASE(to_arith)
+{
+	FixedHash<20> a{};
+	BOOST_CHECK_EQUAL(u160(a), 0);
+
+	FixedHash<32> b("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470");
+	BOOST_CHECK_EQUAL(u256(b), u256("0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"));
+}
+
+BOOST_AUTO_TEST_CASE(comparison)
+{
+	FixedHash<32> a("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470");
+	FixedHash<32> b("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470");
+	FixedHash<32> c("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a471");
+	FixedHash<32> d("233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470c5d2460186f7");
+
+	BOOST_CHECK(a == a);
+	BOOST_CHECK(b == b);
+	BOOST_CHECK(a == b);
+	BOOST_CHECK(b == a);
+	BOOST_CHECK(a != c);
+	BOOST_CHECK(c != a);
+	BOOST_CHECK(a != d);
+	BOOST_CHECK(d != a);
+
+	// Only equal size comparison is supported.
+	BOOST_CHECK(FixedHash<8>{} == FixedHash<8>{});
+	BOOST_CHECK(FixedHash<32>{} != b);
+
+	// Only equal size less than comparison is supported.
+	BOOST_CHECK(!(a < b));
+	BOOST_CHECK(d < c);
+	BOOST_CHECK(FixedHash<32>{} < a);
+}
+
+BOOST_AUTO_TEST_CASE(indexing)
+{
+	// NOTE: uses std::array, so "Accessing a nonexistent element through this operator is undefined behavior."
+
+	FixedHash<32> a("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470");
+	BOOST_CHECK_EQUAL(a[0], 0xc5);
+	BOOST_CHECK_EQUAL(a[1], 0xd2);
+	BOOST_CHECK_EQUAL(a[31], 0x70);
+	a[0] = 0xff;
+	a[31] = 0x54;
+	BOOST_CHECK_EQUAL(a[0], 0xff);
+	BOOST_CHECK_EQUAL(a[1], 0xd2);
+	BOOST_CHECK_EQUAL(a[31], 0x54);
+}
+
+BOOST_AUTO_TEST_CASE(misc)
+{
+	FixedHash<32> a("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470");
+
+	uint8_t* mut_a = a.data();
+	uint8_t const* const_a = a.data();
+	BOOST_CHECK_EQUAL(mut_a, const_a);
+	BOOST_CHECK_EQUAL(memcmp(mut_a, const_a, a.size), 0);
+
+	bytes bytes_a = a.asBytes();
+	bytesRef bytesref_a = a.ref();
+	bytesConstRef bytesconstref_a = a.ref();
+
+	// There's no printing for bytesRef/bytesConstRef
+	BOOST_CHECK(bytes(a.data(), a.data() + a.size) == bytes_a);
+	BOOST_CHECK(bytesRef(a.data(), a.size) == bytesref_a);
+	BOOST_CHECK(bytesConstRef(a.data(), a.size) == bytesconstref_a);
+}
+
+BOOST_AUTO_TEST_CASE(tostream)
+{
+	std::ostringstream out;
+	out << FixedHash<4>("44114411");
+	out << FixedHash<32>{};
+	out << FixedHash<2>("f77f");
+	out << FixedHash<1>("1");
+	BOOST_CHECK_EQUAL(out.str(), "441144110000000000000000000000000000000000000000000000000000000000000000f77f01");
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}