diff --git a/lib/index/mu-indexer.hh b/lib/index/mu-indexer.hh
index c39862b7..67341c25 100644
--- a/lib/index/mu-indexer.hh
+++ b/lib/index/mu-indexer.hh
@@ -25,7 +25,7 @@
 
 namespace Mu {
 
-struct Store;
+class Store;
 
 /// An object abstracting the index process.
 class Indexer {
diff --git a/lib/mu-query.cc b/lib/mu-query.cc
index 86adc626..565d2d49 100644
--- a/lib/mu-query.cc
+++ b/lib/mu-query.cc
@@ -200,7 +200,7 @@ get_query (MuQuery *mqx, const char* searchexpr, bool raw, GError **err) try {
 	Mu::WarningVec warns;
 	const auto tree = Mu::parse (searchexpr, warns,
 				      std::make_unique<MuProc>(mqx->db()));
-	for (const auto w: warns)
+	for (auto&& w: warns)
 		std::cerr << w << std::endl;
 
 	return Mu::xapian_query (tree);
@@ -514,7 +514,7 @@ mu_query_internal (MuQuery *self, const char *searchexpr,
 		ss << tree;
 
 		if (warn) {
-			for (const auto w: warns)
+			for (auto&& w: warns)
 				std::cerr << w << std::endl;
 		}
 
diff --git a/lib/query/mu-xapian.cc b/lib/query/mu-xapian.cc
index 51125946..f058b66a 100644
--- a/lib/query/mu-xapian.cc
+++ b/lib/query/mu-xapian.cc
@@ -79,7 +79,7 @@ xapian_query_value (const Mu::Tree& tree)
 		return make_query(v, parts.front(), true/*maybe-wildcard*/);
 
 	std::vector<Xapian::Query> phvec;
-	for (const auto p: parts)
+	for (const auto& p: parts)
 		phvec.emplace_back(make_query(v, p, false/*no wildcards*/));
 
         return Xapian::Query (Xapian::Query::OP_PHRASE, phvec.begin(), phvec.end());
diff --git a/lib/query/test-tokenizer.cc b/lib/query/test-tokenizer.cc
index 62fa7ef4..5bfaf842 100644
--- a/lib/query/test-tokenizer.cc
+++ b/lib/query/test-tokenizer.cc
@@ -133,7 +133,7 @@ static void
 test_to_string ()
 {
 	std::stringstream ss;
-	for (const auto t: tokenize ("foo and bar xor not cuux or fnorb"))
+	for (auto&& t: tokenize ("foo and bar xor not cuux or fnorb"))
 		ss << t << ' ';
 
 	g_assert_true (ss.str() ==
diff --git a/lib/utils/mu-logger.cc b/lib/utils/mu-logger.cc
index eaeb640f..d9b6decc 100644
--- a/lib/utils/mu-logger.cc
+++ b/lib/utils/mu-logger.cc
@@ -32,7 +32,6 @@
 
 using namespace Mu;
 
-constexpr auto        MuLogDomain      = "mu";
 static bool           MuLogInitialized = false;
 static Mu::LogOptions MuLogOptions;
 static std::ofstream  MuStream;
diff --git a/lib/utils/mu-sexp.hh b/lib/utils/mu-sexp.hh
index 24490096..c90ee6f6 100644
--- a/lib/utils/mu-sexp.hh
+++ b/lib/utils/mu-sexp.hh
@@ -176,8 +176,8 @@ struct Sexp {
                 size_t empty() const { return seq_.empty(); }
 
         private:
-                friend class Sexp;
-                Seq          seq_;
+                friend struct Sexp;
+                Seq           seq_;
         };
 
         /**
diff --git a/mu/mu-cmd-find.cc b/mu/mu-cmd-find.cc
index f6a1e156..7e84a6b8 100644
--- a/mu/mu-cmd-find.cc
+++ b/mu/mu-cmd-find.cc
@@ -541,8 +541,8 @@ static gboolean
 output_sexp (MuMsg *msg, MuMsgIter *iter, const MuConfig *opts, GError **err)
 {
 	const auto *ti{opts->threads ? mu_msg_iter_get_thread_info (iter) : NULL};
-        const auto sexp{Mu:Mu::msg_to_sexp(msg , mu_msg_iter_get_docid (iter), ti,
-                                           MU_MSG_OPTION_HEADERS_ONLY)};
+        const auto sexp{Mu::msg_to_sexp(msg , mu_msg_iter_get_docid (iter), ti,
+                                        MU_MSG_OPTION_HEADERS_ONLY)};
 	fputs (to_string(sexp, !opts->nocolor).c_str(), stdout);
         fputs ("\n", stdout);
 
diff --git a/mu/mu-cmd.cc b/mu/mu-cmd.cc
index 983ea3bf..dede3aba 100644
--- a/mu/mu-cmd.cc
+++ b/mu/mu-cmd.cc
@@ -372,7 +372,7 @@ static bool
 add_path_func (Mu::Store& store, const char *path, GError **err)
 {
         const auto docid = store.add_message (path);
-        g_debug ("added message @ %s, docid=%u", docid);
+        g_debug ("added message @ %s, docid=%u", path, docid);
 
         return true;
 }
@@ -415,7 +415,7 @@ tickle_func (Mu::Store& store, const char *path, GError **err)
 		return false;
 
 	const auto res = mu_msg_tickle (msg, err);
-        g_debug ("tickled %s (%s)", res ? "ok" : "failed");
+        g_debug ("tickled %s (%s)", path, res ? "ok" : "failed");
 	mu_msg_unref (msg);
 
 	return res == TRUE;