diff --git a/keyresolver.cpp b/keyresolver.cpp
index 8c450fa28..13bb9d33d 100644
--- a/keyresolver.cpp
+++ b/keyresolver.cpp
@@ -1487,9 +1487,14 @@ std::vector<GpgME::Key> Kleo::KeyResolver::signingKeys( CryptoMessageFormat f )
 
 
 std::vector<GpgME::Key> Kleo::KeyResolver::selectKeys( const QString & person, const QString & msg, const std::vector<GpgME::Key> & selectedKeys ) const {
+  const bool opgp = containsOpenPGP( mCryptoMessageFormats );
+  const bool x509 = containsSMIME( mCryptoMessageFormats );
+
   Kleo::KeySelectionDialog dlg( i18n("Encryption Key Selection"),
 				msg, selectedKeys,
-				Kleo::KeySelectionDialog::ValidEncryptionKeys,
+                                Kleo::KeySelectionDialog::ValidEncryptionKeys
+                                & ~(opgp ? 0 : Kleo::KeySelectionDialog::OpenPGPKeys)
+                                & ~(x509 ? 0 : Kleo::KeySelectionDialog::SMIMEKeys),
 				true, true ); // multi-selection and "remember choice" box
 
   if ( dlg.exec() != QDialog::Accepted )
diff --git a/kleo_util.h b/kleo_util.h
index 1bdb3219c..3aa5205a0 100644
--- a/kleo_util.h
+++ b/kleo_util.h
@@ -77,5 +77,12 @@ static inline bool isOpenPGP( Kleo::CryptoMessageFormat f ) {
   return f == Kleo::InlineOpenPGPFormat || f == Kleo::OpenPGPMIMEFormat ;
 }
 
+static inline bool containsSMIME( unsigned int f ) {
+  return f & (Kleo::SMIMEFormat|Kleo::SMIMEOpaqueFormat) ;
+}
+
+static inline bool containsOpenPGP( unsigned int f ) {
+  return f & (Kleo::OpenPGPMIMEFormat|Kleo::InlineOpenPGPFormat) ;
+}
 
 #endif // __KDEPIM_KMAIL_KLEO_UTIL_H__