diff --git a/Crypto/include/Poco/Crypto/DigestEngine.h b/Crypto/include/Poco/Crypto/DigestEngine.h
index 65ca98b7e..d44b6f1f4 100644
--- a/Crypto/include/Poco/Crypto/DigestEngine.h
+++ b/Crypto/include/Poco/Crypto/DigestEngine.h
@@ -73,7 +73,7 @@ public:
 	const Poco::DigestEngine::Digest& digest();
 
 protected:
-	void updateImpl(const void* data, unsigned length);
+	void updateImpl(const void* data, std::size_t length);
 	
 private:
 	std::string _name;
diff --git a/Crypto/src/DigestEngine.cpp b/Crypto/src/DigestEngine.cpp
index 6de85067f..59880fab1 100644
--- a/Crypto/src/DigestEngine.cpp
+++ b/Crypto/src/DigestEngine.cpp
@@ -84,7 +84,7 @@ const Poco::DigestEngine::Digest& DigestEngine::digest()
 }
 
 
-void DigestEngine::updateImpl(const void* data, unsigned length)
+void DigestEngine::updateImpl(const void* data, std::size_t length)
 {
 	EVP_DigestUpdate(_ctx, data, length);
 }
diff --git a/Crypto/testsuite/src/CryptoTestSuite.cpp b/Crypto/testsuite/src/CryptoTestSuite.cpp
index d9e855e95..fd7674d07 100644
--- a/Crypto/testsuite/src/CryptoTestSuite.cpp
+++ b/Crypto/testsuite/src/CryptoTestSuite.cpp
@@ -33,6 +33,7 @@
 #include "CryptoTestSuite.h"
 #include "CryptoTest.h"
 #include "RSATest.h"
+#include "DigestEngineTest.h"
 
 
 CppUnit::Test* CryptoTestSuite::suite()
@@ -41,6 +42,7 @@ CppUnit::Test* CryptoTestSuite::suite()
 
 	pSuite->addTest(CryptoTest::suite());
 	pSuite->addTest(RSATest::suite());
+	pSuite->addTest(DigestEngineTest::suite());
 
 	return pSuite;
 }