diff --git a/planet/System.ocg/Math.c b/planet/System.ocg/Math.c
index 69b01d0f5..c98bea06e 100644
--- a/planet/System.ocg/Math.c
+++ b/planet/System.ocg/Math.c
@@ -160,4 +160,10 @@ global func GetSurfaceVector(int x, int y)
 	}
 	
 	return normal;
-}
\ No newline at end of file
+}
+
+// Proper modulo operation.
+global func Mod(a, b)
+{
+	return (a % b + b) % b;
+}
diff --git a/src/lib/C4Random.cpp b/src/lib/C4Random.cpp
index 78fef9d2b..f04edef29 100644
--- a/src/lib/C4Random.cpp
+++ b/src/lib/C4Random.cpp
@@ -21,14 +21,21 @@
 #include "lib/C4Random.h"
 #include "control/C4Record.h"
 
+#include <random>
 #include <pcg/pcg_random.hpp>
 
 int RandomCount = 0;
-static pcg32 RandomRng, UnsyncedRandomRng;
+
+static pcg32 SeededRng()
+{
+	pcg_extras::seed_seq_from<std::random_device> seed_source;
+	return pcg32(seed_source);
+}
+
+static pcg32 RandomRng, UnsyncedRandomRng = SeededRng();
 
 void FixedRandom(uint64_t seed)
 {
-	UnsyncedRandomRng.seed(seed);
 	RandomRng.seed(seed);
 	RandomCount = 0;
 }