diff --git a/base/base_tests/math_test.cpp b/base/base_tests/math_test.cpp
index 78be4eccc3..4feb161c62 100644
--- a/base/base_tests/math_test.cpp
+++ b/base/base_tests/math_test.cpp
@@ -2,6 +2,7 @@
 #include "../math.hpp"
 #include "../../std/limits.hpp"
 
+#include <boost/math/special_functions/next.hpp>
 
 UNIT_TEST(id)
 {
@@ -68,22 +69,14 @@ namespace
 // Returns the next representable floating point value without using conversion to integer.
 template <typename FloatT> FloatT NextFloat(FloatT const x, int dir = 1)
 {
-  FloatT d = dir * numeric_limits<FloatT>::denorm_min();
-  while (true)
-  {
-    FloatT y = x;
-    y += d;
-    if (x != y)
-      return y;
-    d *= 2;
-  }
+  return boost::math::float_advance(x, dir);
 }
 
 template <typename FloatT> void TestMaxULPs()
 {
   for (unsigned int logMaxULPs = 0; logMaxULPs <= 8; ++logMaxULPs)
   {
-    unsigned int const maxULPs = (logMaxULPs == 0 ? 0 : ((1 << logMaxULPs) - 1));
+    unsigned int const maxULPs = (1 << logMaxULPs) - 1;
     for (int base = -1; base <= 1; ++base)
     {
       for (int dir = -1; dir <= 1; dir += 2)
diff --git a/indexer/indexer_tests/mercator_test.cpp b/indexer/indexer_tests/mercator_test.cpp
index 2589b6d4fe..fe951d02f8 100644
--- a/indexer/indexer_tests/mercator_test.cpp
+++ b/indexer/indexer_tests/mercator_test.cpp
@@ -11,8 +11,7 @@
 
 UNIT_TEST(Mercator_Grid)
 {
-  double const eps = 0.0000001;
-  for (int lat = -85; lat <= 85; ++lat)
+  for (int lat = -86; lat <= 86; ++lat)
   {
     for (int lon = -180; lon <= 180; ++lon)
     {
@@ -27,13 +26,6 @@ UNIT_TEST(Mercator_Grid)
 
       // x is actually lon unmodified.
       TEST_ALMOST_EQUAL(x, static_cast<double>(lon), ());
-
-      if (lat == 0)
-      {
-        // TODO: Investigate, how to make Mercator transform more precise.
-        // Error is to large for TEST_ALMOST_EQUAL(y, 0.0, ());
-        TEST_LESS(fabs(y), eps, (lat, y, lat1));
-      }
     }
   }
 }
diff --git a/indexer/mercator.hpp b/indexer/mercator.hpp
index e86d59d848..452e26116e 100644
--- a/indexer/mercator.hpp
+++ b/indexer/mercator.hpp
@@ -43,13 +43,13 @@ struct MercatorBounds
 
   inline static double YToLat(double y)
   {
-    return my::RadToDeg(2.0 * atan(exp(my::DegToRad(y))) - math::pi / 2.0);
+    return my::RadToDeg(2.0 * atan(tanh(0.5 * my::DegToRad(y))));
   }
 
   inline static double LatToY(double lat)
   {
-    lat = my::clamp(lat, -86.0, 86.0);
-    double const res = my::RadToDeg(log(tan(my::DegToRad(45.0 + lat * 0.5))));
+    double const sinx = sin(my::DegToRad(my::clamp(lat, -86.0, 86.0)));
+    double const res = my::RadToDeg(0.5 * log((1.0 + sinx) / (1.0 - sinx)));
     return ClampY(res);
   }