diff --git a/core/src/cost_terms.cpp b/core/src/cost_terms.cpp
index 9ddb94ff2..8cf628537 100644
--- a/core/src/cost_terms.cpp
+++ b/core/src/cost_terms.cpp
@@ -1,4 +1,4 @@
-/*********************************************************************
+/*********************************************************************
  * Software License Agreement (BSD License)
  *
  *  Copyright (c) 2020, Hamburg University
@@ -253,7 +253,7 @@ Clearance::Clearance(bool with_world, bool cumulative, std::string group_propert
   , distance_to_cost{ [](double d) { return 1.0 / (d + 1e-5); } } {}
 
 double Clearance::operator()(const SubTrajectory& s, std::string& comment) const {
-	static const std::string PREFIX{ "Clearance: " };
+	constexpr std::string_view PREFIX{ "Clearance: " };
 
 	collision_detection::DistanceRequest request;
 	request.type =
@@ -298,8 +298,8 @@ double Clearance::operator()(const SubTrajectory& s, std::string& comment) const
 	} };
 
 	auto collision_comment = [=](const auto& distance) {
-		return fmt::format(PREFIX + "allegedly valid solution collides between '{}' and '{}'", distance.link_names[0],
-		                   distance.link_names[1]);
+    	return fmt::format("{}allegedly valid solution collides between '{}' and '{}'", PREFIX,
+					   	   distance.link_names[0], distance.link_names[1]);
 	};
 
 	double distance{ 0.0 };
@@ -313,10 +313,10 @@ double Clearance::operator()(const SubTrajectory& s, std::string& comment) const
 		}
 		distance = distance_data.distance;
 		if (!cumulative)
-			comment = fmt::format(PREFIX + "distance {} between '{}' and '{}'", distance, distance_data.link_names[0],
-			                      distance_data.link_names[1]);
+			comment = fmt::format("{}distance {} between '{}' and '{}'", PREFIX, distance,
+								  distance_data.link_names[0], distance_data.link_names[1]);
 		else
-			comment = fmt::format(PREFIX + "cumulative distance {}", distance);
+			comment = fmt::format("{}cumulative distance {}", PREFIX, distance);
 	} else {  // check trajectory
 		for (size_t i = 0; i < s.trajectory()->getWayPointCount(); ++i) {
 			auto distance_data = check_distance(state, s.trajectory()->getWayPoint(i));
@@ -327,7 +327,8 @@ double Clearance::operator()(const SubTrajectory& s, std::string& comment) const
 			distance += distance_data.distance;
 		}
 		distance /= s.trajectory()->getWayPointCount();
-		comment = fmt::format(PREFIX + "average{} distance: {}", (cumulative ? " cumulative" : ""), distance);
+		comment = fmt::format("{}average{} distance: {}", PREFIX, (cumulative ? " cumulative" : ""),
+							  distance);
 	}
 
 	return distance_to_cost(distance);
diff --git a/core/src/stage.cpp b/core/src/stage.cpp
index b64ce0ab3..6c8ec5c3e 100644
--- a/core/src/stage.cpp
+++ b/core/src/stage.cpp
@@ -909,8 +909,9 @@ bool Connecting::compatible(const InterfaceState& from_state, const InterfaceSta
 	const planning_scene::PlanningSceneConstPtr& from = from_state.scene();
 	const planning_scene::PlanningSceneConstPtr& to = to_state.scene();
 
-	auto false_with_debug = [](auto... args) {
-		RCLCPP_DEBUG_STREAM(rclcpp::get_logger("Connecting"), fmt::format(args...));
+	auto false_with_debug = [](const char* format_str, auto&&... args) {
+		RCLCPP_DEBUG_STREAM(rclcpp::get_logger("Connecting"),
+		                    fmt::format(fmt::runtime(format_str), std::forward<decltype(args)>(args)...));
 		return false;
 	};