diff --git a/emper/Common.cpp b/emper/Common.cpp
index a65097be02648b329eda3b52af2e313393f7768b..ec820e3f98df3c22d9d3058dae18169cace78009 100644
--- a/emper/Common.cpp
+++ b/emper/Common.cpp
@@ -10,7 +10,7 @@ void die(const char* message, bool usePerror) {
 	if (usePerror) {
 		std::perror(message);
 	} else {
-		std::cout << message << std::endl;
+		std::cerr << message << std::endl;
 	}
 	exit(EXIT_FAILURE);
 }
diff --git a/emper/Common.hpp b/emper/Common.hpp
index fdda0ccfb80f50391047787b7d28816e8982fd19..72136a72e4a0ed1ba867112f22f7549dd876cfa6 100644
--- a/emper/Common.hpp
+++ b/emper/Common.hpp
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
-// Copyright © 2020 Florian Schmaus
+// Copyright © 2020-2021 Florian Schmaus, Florian Fischer
 #pragma once
 
 #include <functional>
@@ -9,8 +9,16 @@ using func_t = std::function<void()>;
 #define STRINGIFY(x) #x
 #define TOSTRING(x) STRINGIFY(x)
 #define DIE die(__FILE__ ":" TOSTRING(__LINE__), false)
-#define DIE_MSG(x) die(__FILE__ ":" TOSTRING(__LINE__) " " #x, false)
-#define DIE_MSG_ERRNO(x) die(__FILE__ ":" TOSTRING(__LINE__) " " #x, true)
+
+// See Debug.hpp why we disable clang-format for the multi statement macro definitions
+// clang-format off
+
+// NOLINTNEXTLINE(bugprone-macro-parentheses)
+#define DIE_MSG(x) do { std::stringstream sst; sst << __FILE__ ":" TOSTRING(__LINE__) " " << x; die(sst.str().c_str(), false); } while (false)
+// NOLINTNEXTLINE(bugprone-macro-parentheses)
+#define DIE_MSG_ERRNO(x) do { std::stringstream sst; sst << __FILE__ ":" TOSTRING(__LINE__) " " << x; die(sst.str().c_str(), true); } while (false)
+
+// clang-format on
 
 // We compile with -fno-exceptions for the moment.
 //#define THROW(x) do { throw std::runtime_error(x); } while (false)
diff --git a/emper/strategies/laws/LawsDispatcher.cpp b/emper/strategies/laws/LawsDispatcher.cpp
index 94a82e7bc83562d6bfae8c0f3ffe767655316922..358494c9577c0129500e9e8f421cfd9e47077490 100644
--- a/emper/strategies/laws/LawsDispatcher.cpp
+++ b/emper/strategies/laws/LawsDispatcher.cpp
@@ -48,7 +48,7 @@ void LawsDispatcher::dispatchLoop() {
 						lawsStrategy.dispatchedFiberFromAnywhere.fetch_add(1, std::memory_order_relaxed);
 						break;
 					default:
-						DIE_MSG("Unknown fiber flag: " << flag);
+						DIE_MSG("Unknown fiber source: " << next.metadata);
 						break;
 				}
 			}