diff --git a/core/shannon_entropy.cc b/core/shannon_entropy.cc
index 4645777..6da7b7d 100644
--- a/core/shannon_entropy.cc
+++ b/core/shannon_entropy.cc
@@ -21,7 +21,7 @@ int64_t ComputeShannonEntropy(const uint32_t *symbols, int num_symbols,
       // Compute Shannon entropy for the symbol.
       total_bits +=
           symbol_frequencies[i] *
-          std::log2(static_cast<double>(symbol_frequencies[i]) / num_symbols_d);
+          log2(static_cast<double>(symbol_frequencies[i]) / num_symbols_d);
     }
   }
   if (out_num_unique_symbols)