diff --git a/src/core/random_func.cpp b/src/core/random_func.cpp
--- a/src/core/random_func.cpp
+++ b/src/core/random_func.cpp
@@ -28,101 +28,6 @@ void Randomizer::SetSeed(uint32 seed)
 	this->state[1] = seed;
 }
 
-#ifdef MERSENNE_TWISTER
-// Source code for Mersenne Twister.
-// A Random number generator with much higher quality random numbers.
-
-#define N              (624)                 // length of _mt_state vector
-#define M              (397)                 // a period parameter
-#define K              (0x9908B0DFU)         // a magic constant
-#define hiBit(u)       ((u) & 0x80000000U)   // mask all but highest   bit of u
-#define loBit(u)       ((u) & 0x00000001U)   // mask all but lowest    bit of u
-#define loBits(u)      ((u) & 0x7FFFFFFFU)   // mask     the highest   bit of u
-#define mixBits(u, v)  (hiBit(u)|loBits(v))  // move hi bit of u to hi bit of v
-
-static uint32 _mt_state[N+1];     // _mt_state vector + 1 extra to not violate ANSI C
-static uint32 *_mt_next;          // _mt_next random value is computed from here
-static int    _mt_left = -1;      // can *_mt_next++ this many times before reloading
-
-void SetRandomSeed(register uint32 seed)
-{
-	register uint32 *s = _mt_state;
-	_mt_left = 0;
-
-	seed |= 1U;
-	seed &= 0xFFFFFFFFU;
-
-	*s = seed;
-
-	for (register uint i = N; i != 0; i--) {
-		seed *= 69069U;
-		*s++;
-		*s = seed & 0xFFFFFFFFU;
-	}
-}
-
-static uint32 ReloadRandom()
-{
-	if (_mt_left < -1) SetRandomSeed(4357U);
-
-	_mt_left = N - 1;
-	_mt_next = _mt_state + 1;
-
-	register uint32 *p0 = _mt_state;
-	register uint32 *p2 = _mt_state + 2;
-	register uint32 *pM = _mt_state + M;
-
-	register uint32 s0 = _mt_state[0];
-	register uint32 s1 = _mt_state[1];
-
-	register uint i = 0;
-
-	for (i = (N - M + 1); i != 0; i--) {
-		s0 = s1;
-		s1 = *p2;
-		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-		*p0++;
-		*p2++;
-		*pM++;
-	}
-
-	pM = _mt_state;
-
-	for (i = M; i != 0; i--) {
-		s0 = s1;
-		s1 = *p2;
-		*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-		*p0++;
-		*p2++;
-		*pM++;
-	}
-
-	s1 = _mt_state[0];
-	*p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-
-	s1 ^= (s1 >> 11);
-	s1 ^= (s1 <<  7) & 0x9D2C5680U;
-	s1 ^= (s1 << 15) & 0xEFC60000U;
-	s1 ^= (s1 >> 18);
-	return s1;
-}
-
-uint32 Random()
-{
-	_mt_left--;
-	if (_mt_left < 0) return ReloadRandom();
-
-	uint32 y = *_mt_next;
-	*_mt_next++;
-
-	y ^= (y >> 11);
-	y ^= (y <<  7) & 0x9D2C5680U;
-	y ^= (y << 15) & 0xEFC60000U;
-	y ^= (y >> 18);
-	return y;
-}
-
-#else /* MERSENNE_TWISTER */
 void SetRandomSeed(uint32 seed)
 {
 	_random.SetSeed(seed);
@@ -142,12 +47,9 @@ uint32 DoRandom(int line, const char *fi
 
 	return _random.Next();
 }
-#endif /* RANDOM_DEBUG */
-#endif /* MERSENNE_TWISTER */
 
-#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
 uint DoRandomRange(uint max, int line, const char *file)
 {
 	return GB(DoRandom(line, file), 0, 16) * max >> 16;
 }
-#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+#endif /* RANDOM_DEBUG */
diff --git a/src/core/random_func.hpp b/src/core/random_func.hpp
--- a/src/core/random_func.hpp
+++ b/src/core/random_func.hpp
@@ -23,10 +23,6 @@
 //#define RANDOM_DEBUG
 
 
-// Enable this to produce higher quality random numbers.
-// Doesn't work with network yet.
-// #define MERSENNE_TWISTER
-
 /**
  * Structure to encapsulate the pseudo random number generators.
  */