diff --git a/Makefile b/Makefile
index 2d45683..202e4e3 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ MAKEFLAGS="-j $(grep -c ^processor /proc/cpuinfo)"
 CXXFLAGS:=$(CXXFLAGS) -std=c++20 -Wall -Wextra -Werror=switch -Werror=return-type -Werror=unused-result
 CPPFLAGS:=$(CPPFLAGS) -Ilib/expected/ -Ilib/ut/ -Ilib/midi/include -Isrc/ -Ilib/bestline/
 RELEASE_FLAGS=-O3
-DEBUG_FLAGS=-O0 -ggdb -fsanitize=undefined
+DEBUG_FLAGS=-O0 -ggdb -fsanitize=undefined -DDebug
 CXX=g++
 
 LDFLAGS=-L./lib/midi/
diff --git a/src/errors.cc b/src/errors.cc
index 8303c8d..743644d 100644
--- a/src/errors.cc
+++ b/src/errors.cc
@@ -2,6 +2,7 @@
 
 #include <iostream>
 #include <sstream>
+#include <stdexcept>
 
 template<typename T, typename ...Params>
 concept Callable = requires(T t, Params ...params) { t(params...); };
@@ -79,6 +80,10 @@ static void encourage_contact(std::ostream &os)
 void assert(bool condition, std::string message, Location loc)
 {
 	if (condition) return;
+#if Debug
+	std::cout << "assertion failed at " << loc << " with message: " << message << std::endl;
+	throw std::runtime_error(message);
+#else
 	error_heading(std::cerr, loc, Error_Level::Bug, "Assertion in interpreter");
 
 	if (not message.empty())
@@ -87,10 +92,18 @@ void assert(bool condition, std::string message, Location loc)
 	encourage_contact(std::cerr);
 
 	std::exit(42);
+#endif
 }
 
-[[noreturn]] void unimplemented(std::string_view message, Location loc)
+#if !Debug
+[[noreturn]]
+#endif
+void unimplemented(std::string_view message, Location loc)
 {
+#if Debug
+	std::cout << "unreachable state reached at " << loc << " with message: " << message << std::endl;
+	throw std::runtime_error(std::string(message));
+#else
 	error_heading(std::cerr, loc, Error_Level::Bug, "This part of interpreter was not implemented yet");
 
 	if (not message.empty()) {
@@ -100,13 +113,22 @@ void assert(bool condition, std::string message, Location loc)
 	encourage_contact(std::cerr);
 
 	std::exit(42);
+#endif
 }
 
-[[noreturn]] void unreachable(Location loc)
+#if !Debug
+[[noreturn]]
+#endif
+void unreachable(Location loc)
 {
+#if Debug
+	std::cout << "unreachable state reached at " << loc << std::endl;
+	throw std::runtime_error("reached unreachable");
+#else
 	error_heading(std::cerr, loc, Error_Level::Bug, "Reached unreachable state");
 	encourage_contact(std::cerr);
 	std::exit(42);
+#endif
 }
 
 std::ostream& operator<<(std::ostream& os, Error const& err)