diff --git a/src/core/pistring.cpp b/src/core/pistring.cpp
index 2f6ba602..2b2351ac 100755
--- a/src/core/pistring.cpp
+++ b/src/core/pistring.cpp
@@ -89,8 +89,10 @@ int wctomb(char * c, wchar_t w) {*c = ((char * )&w)[0]; return 1;}
 
 PIString PIString::itos(const int num) {pisprintf("%d", num); return PIString(ch);}
 PIString PIString::ltos(const long num) {pisprintf("%ld", num); return PIString(ch);}
+PIString PIString::lltos(const llong num) {pisprintf("%lld", num); return PIString(ch);}
 PIString PIString::uitos(const uint num) {pisprintf("%u", num); return PIString(ch);}
 PIString PIString::ultos(const ulong num) {pisprintf("%lu", num); return PIString(ch);}
+PIString PIString::ulltos(const ullong num) {pisprintf("%llu", num); return PIString(ch);}
 PIString PIString::ftos(const float num) {pisprintf("%.8f", num); return PIString(ch);}
 PIString PIString::dtos(const double num) {pisprintf("%.8f", num); return PIString(ch);}
 
diff --git a/src/core/pistring.h b/src/core/pistring.h
index 5249b68d..2b76528a 100755
--- a/src/core/pistring.h
+++ b/src/core/pistring.h
@@ -754,15 +754,17 @@ private:
 	
 	static PIString itos(const int num);
 	static PIString ltos(const long num);
+	static PIString lltos(const llong num);
 	static PIString uitos(const uint num);
 	static PIString ultos(const ulong num);
+	static PIString ulltos(const ullong num);
 	static PIString ftos(const float num);
 	static PIString dtos(const double num);
 	static PIString fromNumberBaseS(const llong value, int base = 10, bool * ok = 0) {
 		if (value == 0) return PIString("0");
 		if (base < 2 || base > 40) {if (ok != 0) *ok = false; return PIString();}
 		if (ok != 0) *ok = true;
-		if (base == 10) return itos(value);
+		if (base == 10) return lltos(value);
 		PIString ret;
 		llong v = value < 0 ? -value : value, cn;
 		int b = base;
@@ -780,7 +782,7 @@ private:
 		if (value == 0) return PIString("0");
 		if (base < 2 || base > 40) {if (ok != 0) *ok = false; return PIString();}
 		if (ok != 0) *ok = true;
-		if (base == 10) return itos(value);
+		if (base == 10) return ulltos(value);
 		PIString ret;
 		ullong v = value, cn;
 		int b = base;