diff --git a/Crypto/include/Poco/Crypto/OpenSSLInitializer.h b/Crypto/include/Poco/Crypto/OpenSSLInitializer.h
index b616f08fa4..f4d1d6a415 100644
--- a/Crypto/include/Poco/Crypto/OpenSSLInitializer.h
+++ b/Crypto/include/Poco/Crypto/OpenSSLInitializer.h
@@ -84,8 +84,9 @@ class Crypto_API OpenSSLInitializer
 	static void dynlockDestroy(struct CRYPTO_dynlock_value* lock, const char* file, int line);
 
 private:
+	static Poco::FastMutex _mutex;
 	static Poco::FastMutex* _mutexes;
-	static Poco::AtomicCounter _rc;
+	static int _rc;
     static bool _disableSSLInitialization;
 };
 
diff --git a/Crypto/src/OpenSSLInitializer.cpp b/Crypto/src/OpenSSLInitializer.cpp
index 3808341723..6a74ba8127 100644
--- a/Crypto/src/OpenSSLInitializer.cpp
+++ b/Crypto/src/OpenSSLInitializer.cpp
@@ -33,9 +33,9 @@ using Poco::Thread;
 namespace Poco {
 namespace Crypto {
 
-
+Poco::FastMutex OpenSSLInitializer::_mutex;
 Poco::FastMutex* OpenSSLInitializer::_mutexes(0);
-Poco::AtomicCounter OpenSSLInitializer::_rc;
+int OpenSSLInitializer::_rc(0);
 bool OpenSSLInitializer::_disableSSLInitialization = false;
 
 OpenSSLInitializer::OpenSSLInitializer()
@@ -59,6 +59,7 @@ OpenSSLInitializer::~OpenSSLInitializer()
 
 void OpenSSLInitializer::initialize()
 {
+	FastMutex::ScopedLock lock(_mutex);
 	if (++_rc == 1)
 	{
 #if OPENSSL_VERSION_NUMBER >= 0x0907000L
@@ -104,6 +105,7 @@ void OpenSSLInitializer::initialize()
 
 void OpenSSLInitializer::uninitialize()
 {
+	FastMutex::ScopedLock lock(_mutex);
 	if (--_rc == 0)
 	{
         if(_mutexes != NULL) {