@@ -191,12 +191,12 @@
 #endif
 
 void
 of_invocation_invoke(OFInvocation *invocation)
 {
-	OFMethodSignature *methodSignature = [invocation methodSignature];
-	size_t numberOfArguments = [methodSignature numberOfArguments];
+	OFMethodSignature *methodSignature = invocation.methodSignature;
+	size_t numberOfArguments = methodSignature.numberOfArguments;
 	struct call_context *context;
 	const char *typeEncoding;
 	uint_fast8_t currentGPR = 0, currentSSE = 0;
 
 	if ((context = calloc(sizeof(*context), 1)) == NULL)
@@ -308,11 +308,11 @@
 			free(context);
 			@throw [OFInvalidFormatException exception];
 		}
 	}
 
-	typeEncoding = [methodSignature methodReturnType];
+	typeEncoding = methodSignature.methodReturnType;
 
 	if (*typeEncoding == 'r')
 		typeEncoding++;
 
 	switch (*typeEncoding) {