diff --git a/Utility/StringMap.h b/Utility/StringMap.h
index 1b8d397..6281999 100644
--- a/Utility/StringMap.h
+++ b/Utility/StringMap.h
@@ -4,6 +4,8 @@ static_assert( __cplusplus > 2020'99 );
 
 #include <Alepha/Alepha.h>
 
+#include <cmath>
+
 #include <map>
 #include <string>
 #include <exception>
@@ -55,7 +57,7 @@ namespace Alepha::Hydrogen::Utility  ::detail:: StringMap_m
 						} );
 
 					if( closest == end( storage ) ) throw std::out_of_range{ IOStreams::String() << "The key `" << key << "` could not be found." };
-					else if( optimalStringDistance( closest->first, key ) < sqrt( key.size() ) )
+					else if( optimalStringDistance( closest->first, key ) < std::sqrt( key.size() ) )
 					{
 						throw std::out_of_range{ IOStreams::String() << "The key `" << key << "` could not be found.  Did you mean `"
 								<< closest->first << "`?"  };