diff --git a/fairmq/ProgOptions.cxx b/fairmq/ProgOptions.cxx
index d3465321..2fe63f7b 100644
--- a/fairmq/ProgOptions.cxx
+++ b/fairmq/ProgOptions.cxx
@@ -169,7 +169,7 @@ unordered_map<string, int> ProgOptions::GetChannelInfoImpl() const
     for (const auto& m : fVarMap) {
         if (boost::regex_match(m.first, re)) {
             string chan = m.first.substr(6);
-            string::size_type n = chan.find(".");
+            string::size_type n = chan.find('.');
             string chanName = chan.substr(0, n);
 
             if (info.find(chanName) == info.end()) {
diff --git a/fairmq/StateMachine.cxx b/fairmq/StateMachine.cxx
index 07f773f6..81c1d339 100644
--- a/fairmq/StateMachine.cxx
+++ b/fairmq/StateMachine.cxx
@@ -222,9 +222,9 @@ struct Machine_ : public state_machine_def<Machine_>
         bmpl::for_each<AllStates, wrap<bmpl::placeholders::_1>>(get_state_name<RecursiveStt>(stateName, state));
 
         stateName = boost::core::demangle(stateName.c_str());
-        size_t pos = stateName.rfind(":");
+        size_t pos = stateName.rfind(':');
         stateName = stateName.substr(pos + 1);
-        size_t pos2 = stateName.rfind("_");
+        size_t pos2 = stateName.rfind('_');
         stateName = stateName.substr(0, pos2);
 
         if (stateName != "OK") {