diff --git a/util.h b/util.h
index df8fb88..e8ba046 100644
--- a/util.h
+++ b/util.h
@@ -3,6 +3,7 @@
 
 #include <limits>
 #include <random>
+#include <ctime>
 
 const double infinity = std::numeric_limits<double>::infinity();
 const double pi = 3.1415926535897932385;
@@ -13,7 +14,7 @@ inline double degrees_to_radians(double degrees) {
 
 inline double random_double() {
     static std::uniform_real_distribution<double> distribution(0.0, 1.0);
-    static std::mt19937 generator;
+    static std::mt19937 generator(std::time(nullptr));
     return distribution(generator);
 }