diff --git a/src/parser/PrismParser/BaseGrammar.h b/src/parser/PrismParser/BaseGrammar.h
index 0846eb12c..4bf4f3265 100644
--- a/src/parser/PrismParser/BaseGrammar.h
+++ b/src/parser/PrismParser/BaseGrammar.h
@@ -21,7 +21,7 @@ namespace prism {
 	public:
 		BaseGrammar(std::shared_ptr<VariableState>& state) : state(state) {}
 
-		static T& instance(std::shared_ptr<VariableState>& state = nullptr) {
+		static T& instance(std::shared_ptr<VariableState> state = nullptr) {
 			if (BaseGrammar::instanceObject == nullptr) {
 				BaseGrammar::instanceObject = std::shared_ptr<T>(new T(state));
 				if (!state->firstRun) BaseGrammar::instanceObject->secondRun();
diff --git a/src/storm.cpp b/src/storm.cpp
index bcdf399d7..b01d21951 100644
--- a/src/storm.cpp
+++ b/src/storm.cpp
@@ -44,12 +44,14 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <iostream>
+#include <iomanip>
 
 void printUsage() {
 	struct rusage ru;
 	getrusage(RUSAGE_SELF, &ru);
 
 	std::cout << "Memory Usage: " << ru.ru_maxrss << "kB" << std::endl;
+	std::cout << "CPU time: " << ru.ru_utime.tv_sec << "." << std::setw(3) << std::setfill('0') << ru.ru_utime.tv_usec/1000 << " seconds" << std::endl;
 }