diff --git a/tests/test_ihex.py b/tests/test_ihex.py
new file mode 100644
index 0000000..4828c48
--- /dev/null
+++ b/tests/test_ihex.py
@@ -0,0 +1,62 @@
+#
+# Copyright (c) 2021 Grigori Goronzy <greg@chown.ath.cx>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+
+import unittest
+import stcgal.ihex
+
+class IHEXTests(unittest.TestCase):
+    """Tests for IHEX reader"""
+
+    def test_simple(self):
+        """Test reading a basic, valid file"""
+        lines = [
+            b":0B00000068656C6C6F5F776F726C645A",
+            b":00000001FF"
+        ]
+        bindata = stcgal.ihex.IHex.read(lines).extract_data()
+        self.assertEqual(bindata, b"hello_world")
+
+    def test_empty(self):
+        """Test reading an empty file"""
+        lines = []
+        bindata = stcgal.ihex.IHex.read(lines).extract_data()
+        self.assertEqual(bindata, b"")
+
+    def test_invalid(self):
+        """Test invalid encoded data"""
+        lines = [
+            ":abc"
+        ]
+        with self.assertRaises(ValueError):
+            stcgal.ihex.IHex.read(lines)
+
+    def test_roundtrip(self):
+        """Test round-trip through encoder/decoder"""
+        bindata = b"12345678"
+        for mode in (8, 16, 32):
+            with self.subTest(mode):
+                hexer = stcgal.ihex.IHex()
+                hexer.set_mode(mode)
+                hexer.insert_data(0, bindata)
+                encoded = hexer.write().encode("ASCII").splitlines()
+                decoded = stcgal.ihex.IHex.read(encoded).extract_data()
+                self.assertEqual(decoded, bindata)