diff --git a/include/openmc/plot.h b/include/openmc/plot.h
index 3e97e2544c0..ba82f43e27a 100644
--- a/include/openmc/plot.h
+++ b/include/openmc/plot.h
@@ -1,6 +1,7 @@
 #ifndef OPENMC_PLOT_H
 #define OPENMC_PLOT_H
 
+#include <cmath>
 #include <sstream>
 #include <unordered_map>
 
@@ -200,7 +201,7 @@ T SlicePlotBase::get_map() const
   xyz[out_i] = origin_[out_i] + width_[1] / 2. - out_pixel / 2.;
 
   // arbitrary direction
-  Direction dir = {0.7071, 0.7071, 0.0};
+  Direction dir = {1. / std::sqrt(2.), 1. / std::sqrt(2.), 0.0};
 
 #pragma omp parallel
   {
diff --git a/src/volume_calc.cpp b/src/volume_calc.cpp
index 859a0d5ac1b..6a47e9490b5 100644
--- a/src/volume_calc.cpp
+++ b/src/volume_calc.cpp
@@ -159,7 +159,7 @@ vector<VolumeCalculation::Result> VolumeCalculation::execute() const
         p.n_coord() = 1;
         Position xi {prn(&seed), prn(&seed), prn(&seed)};
         p.r() = lower_left_ + xi * (upper_right_ - lower_left_);
-        p.u() = {0.5, 0.5, 0.5};
+        p.u() = {1. / std::sqrt(3.), 1. / std::sqrt(3.), 1. / std::sqrt(3.)};
 
         // If this location is not in the geometry at all, move on to next block
         if (!exhaustive_find_cell(p))