diff --git a/passphrase_cache.cc b/passphrase_cache.cc
index d13973a..41bfeda 100644
--- a/passphrase_cache.cc
+++ b/passphrase_cache.cc
@@ -1,6 +1,22 @@
 #include "passphrase_cache.hh"
 
 namespace pEp {
+    PassphraseCache::PassphraseCache(int max_size, duration timeout) :
+            _max_size(max_size), _timeout(timeout), _which(_cache.end())
+    { }
+
+    PassphraseCache::PassphraseCache(const PassphraseCache& second) :
+            _cache(second._cache), _max_size(second._max_size),
+            _timeout(second._timeout), _which(_cache.end())
+    {
+        cleanup();
+    }
+
+    PassphraseCache PassphraseCache::operator=(const PassphraseCache& second)
+    {
+        return second;
+    }
+
     const char *PassphraseCache::add(std::string passphrase)
     {
         std::lock_guard<std::mutex> lock(_mtx);
diff --git a/passphrase_cache.hh b/passphrase_cache.hh
index 91f80ea..2b7d0c8 100644
--- a/passphrase_cache.hh
+++ b/passphrase_cache.hh
@@ -40,13 +40,10 @@ namespace pEp {
         };
 
         PassphraseCache(int max_size=20, duration timeout =
-                std::chrono::minutes(10)) : _max_size(max_size),
-                    _timeout(timeout), _which(_cache.end()) { }
+                std::chrono::minutes(10));
         ~PassphraseCache() { }
-        PassphraseCache(const PassphraseCache& second) : _cache(second._cache),
-                _max_size(second._max_size), _timeout(second._timeout),
-                _which(_cache.end()) { }
-        PassphraseCache operator=(const PassphraseCache& second) { return second; }
+        PassphraseCache(const PassphraseCache& second);
+        PassphraseCache operator=(const PassphraseCache& second);
 
         // adding a passphrase to the cache, which will timeout