diff --git a/TheModernCppChallenge/app/src/main/cpp/Problem_5.hpp b/TheModernCppChallenge/app/src/main/cpp/Problem_5.hpp
index b0131ff..d7e1f81 100644
--- a/TheModernCppChallenge/app/src/main/cpp/Problem_5.hpp
+++ b/TheModernCppChallenge/app/src/main/cpp/Problem_5.hpp
@@ -7,7 +7,7 @@
 #include <vector>
 #include <utility>
 
-bool isSexyPrimePair(unsigned int firstNumber, unsigned int secondNumber)
+static const bool isSexyPrimePair(unsigned int firstNumber, unsigned int secondNumber)
 {
     return (std::abs(static_cast<int>(firstNumber - secondNumber)) == 6) && isPrime(firstNumber) && isPrime(secondNumber);
 }