diff --git a/CMakeLists.txt b/CMakeLists.txt
index a42ba8d..2798b6a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -447,3 +447,17 @@ if(ARITH_ENABLED)
 else()
     message(STATUS "Arithmetic Coding: Disabled")
 endif()
+
+
+
+find_package(Python3 COMPONENTS Interpreter Development)
+
+if (Python3_FOUND)
+  enable_testing()
+  add_test(NAME unittests
+	 COMMAND ${Python3_EXECUTABLE} test.py
+	 WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/test
+	 )
+
+  set_property(TEST unittests PROPERTY ENVIRONMENT "JPEGOPTIM=$<TARGET_FILE:jpegoptim>")
+endif()
diff --git a/test/jpegoptim_test2.jpg b/test/jpegoptim_test2.jpg
index c629711..ee0a3fd 100644
Binary files a/test/jpegoptim_test2.jpg and b/test/jpegoptim_test2.jpg differ
diff --git a/test/test.py b/test/test.py
index cf002bc..d8ce86f 100755
--- a/test/test.py
+++ b/test/test.py
@@ -31,6 +31,10 @@ class JpegoptimTests(unittest.TestCase):
     program = '../jpegoptim'
     debug = False
 
+    def setUp(self):
+        if "JPEGOPTIM" in os.environ:
+            self.program = os.environ["JPEGOPTIM"]
+
     def run_test(self, args, check=True, directory=None):
         """execute jpegoptim for a test"""
         command = [self.program] + args