diff --git a/src/Expr.h b/src/Expr.h
index 95c1167abe..f341f5a9c4 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -218,9 +218,10 @@ protected:
 	// TYPE_ERROR.
 	void ExprError(const char msg[]);
 
-	void RuntimeError(const std::string& msg) const;
-
-	void RuntimeErrorWithCallStack(const std::string& msg) const;
+	// These two functions both call Reporter::RuntimeError or Reporter::ExprRuntimeError,
+	// both of which are marked as [[noreturn]].
+	[[noreturn]] void RuntimeError(const std::string& msg) const;
+	[[noreturn]] void RuntimeErrorWithCallStack(const std::string& msg) const;
 
 	BroExprTag tag;
 	IntrusivePtr<BroType> type;
diff --git a/src/Reporter.h b/src/Reporter.h
index cdb0bc13e9..97f1759963 100644
--- a/src/Reporter.h
+++ b/src/Reporter.h
@@ -74,11 +74,11 @@ public:
 
 	// Report a runtime error in evaluating a Bro script expression. This
 	// function will not return but raise an InterpreterException.
-	void ExprRuntimeError(const Expr* expr, const char* fmt, ...) __attribute__((format(printf, 3, 4)));
+	[[noreturn]] void ExprRuntimeError(const Expr* expr, const char* fmt, ...) __attribute__((format(printf, 3, 4)));
 
 	// Report a runtime error in evaluating a Bro script expression. This
 	// function will not return but raise an InterpreterException.
-	void RuntimeError(const Location* location, const char* fmt, ...) __attribute__((format(printf, 3, 4)));
+	[[noreturn]] void RuntimeError(const Location* location, const char* fmt, ...) __attribute__((format(printf, 3, 4)));
 
 	// Report a traffic weirdness, i.e., an unexpected protocol situation
 	// that may lead to incorrectly processing a connnection.