diff --git a/lib/index/mu-indexer.cc b/lib/index/mu-indexer.cc
index 4c9bd19f..8875958f 100644
--- a/lib/index/mu-indexer.cc
+++ b/lib/index/mu-indexer.cc
@@ -140,8 +140,8 @@ Indexer::Private::handler (const std::string& fullpath, struct stat *statbuf,
         case Scanner::HandleType::File: {
 
                 if ((size_t)statbuf->st_size > max_message_size_) {
-                        g_debug ("skip %s (too big: %zu bytes)",
-                                 fullpath.c_str(), statbuf->st_size);
+                        g_debug ("skip %s (too big: %" G_GINT64_FORMAT " bytes)",
+                                 fullpath.c_str(), (gint64)statbuf->st_size);
                         return false;
                 }
 
diff --git a/lib/test-mu-contacts.cc b/lib/test-mu-contacts.cc
index 2c7bad81..208943af 100644
--- a/lib/test-mu-contacts.cc
+++ b/lib/test-mu-contacts.cc
@@ -32,22 +32,22 @@ test_mu_contacts_01()
         g_assert_true (contacts.empty());
         g_assert_cmpuint (contacts.size(), ==, 0);
 
-        contacts.add(std::move(Mu::ContactInfo ("Foo <foo.bar@example.com>",
-                                                "foo.bar@example.com", "Foo", false, 12345)));
+        contacts.add(Mu::ContactInfo ("Foo <foo.bar@example.com>",
+                                                "foo.bar@example.com", "Foo", false, 12345));
         g_assert_false (contacts.empty());
         g_assert_cmpuint (contacts.size(), ==, 1);
 
-        contacts.add(std::move(Mu::ContactInfo ("Cuux <cuux.fnorb@example.com>",
-                                                "cuux@example.com", "Cuux", false, 54321)));
+        contacts.add(Mu::ContactInfo ("Cuux <cuux.fnorb@example.com>",
+                                                "cuux@example.com", "Cuux", false, 54321));
 
         g_assert_cmpuint (contacts.size(), ==, 2);
 
-        contacts.add(std::move(Mu::ContactInfo ("foo.bar@example.com",
-                                                "foo.bar@example.com", "Foo", false, 77777)));
+        contacts.add(Mu::ContactInfo ("foo.bar@example.com",
+                                                "foo.bar@example.com", "Foo", false, 77777));
         g_assert_cmpuint (contacts.size(), ==, 2);
 
-        contacts.add(std::move(Mu::ContactInfo ("Foo.Bar@Example.Com",
-                                                "Foo.Bar@Example.Com", "Foo", false, 88888)));
+        contacts.add(Mu::ContactInfo ("Foo.Bar@Example.Com",
+                                                "Foo.Bar@Example.Com", "Foo", false, 88888));
         g_assert_cmpuint (contacts.size(), ==, 2);
         // note: replaces first.
 
diff --git a/mu/mu-cmd-server.cc b/mu/mu-cmd-server.cc
index 56bf14ee..afd75850 100644
--- a/mu/mu-cmd-server.cc
+++ b/mu/mu-cmd-server.cc
@@ -66,10 +66,12 @@ install_sig_handler (void)
 static void
 cookie(size_t n)
 {
+        const auto num{static_cast<unsigned>(n)};
+
         if (tty) // for testing.
-                ::printf ("[%x]", n);
+                ::printf ("[%x]", num);
         else
-                ::printf (COOKIE_PRE "%x" COOKIE_POST, n);
+                ::printf (COOKIE_PRE "%x" COOKIE_POST, num);
 }
 
 static void