diff --git a/passphrase_cache.hh b/passphrase_cache.hh
index 42ffb32..69936a8 100644
--- a/passphrase_cache.hh
+++ b/passphrase_cache.hh
@@ -33,8 +33,10 @@ namespace pEp {
     public:
         struct Empty : public std::underflow_error {
             Empty() : std::underflow_error("passphrase cache empty") { }
+        };
         struct Exhausted : public std::underflow_error {
             Exhausted() : std::underflow_error("out of passphrases") { }
+        };
 
         PassphraseCache(int max_size=20, duration timeout =
                 std::chrono::minutes(10)) : _max_size(max_size),