diff --git a/src/doomerrors.h b/src/doomerrors.h
index 831db4a91e..52bc3c12bb 100644
--- a/src/doomerrors.h
+++ b/src/doomerrors.h
@@ -71,7 +71,7 @@ public:
 		else
 			return NULL;
 	}
-	char const *what() const override
+	char const *what() const noexcept override
 	{
 		return m_Message;
 	}
diff --git a/src/posix/sdl/i_main.cpp b/src/posix/sdl/i_main.cpp
index 8e7230777e..0c23892948 100644
--- a/src/posix/sdl/i_main.cpp
+++ b/src/posix/sdl/i_main.cpp
@@ -265,11 +265,11 @@ int main (int argc, char **argv)
 			fprintf (stderr, "%s\n", error.what ());
 
 #ifdef __APPLE__
-		Mac_I_FatalError(error.GetMessage());
+		Mac_I_FatalError(error.what());
 #endif // __APPLE__
 
 #ifdef __linux__
-		Linux_I_FatalError(error.GetMessage());
+		Linux_I_FatalError(error.what());
 #endif // __linux__
 
 		exit (-1);