diff --git a/include/aoc/GuardGallivant.hpp b/include/aoc/GuardGallivant.hpp
index ccf3b8d..58d91c1 100644
--- a/include/aoc/GuardGallivant.hpp
+++ b/include/aoc/GuardGallivant.hpp
@@ -29,7 +29,7 @@ class GuardGallivant
     Point2 start_{};
     void visitPosition(const Point2& current);
     size_t turnDirection(const size_t current) const;
-    size_t getStartDirectionIndex() const;
+    const size_t getStartDirectionIndex() const;
     const char getStartChar() const;
     const char getVisitedChar() const;
     const char getObstructionChar() const;
diff --git a/src/GuardGallivant.cpp b/src/GuardGallivant.cpp
index c6c1a7e..b14cfc8 100644
--- a/src/GuardGallivant.cpp
+++ b/src/GuardGallivant.cpp
@@ -70,7 +70,7 @@ size_t GuardGallivant::turnDirection(const size_t current) const
     return current == 0 ? 3 : current - 1;
 }
 
-size_t GuardGallivant::getStartDirectionIndex() const
+const size_t GuardGallivant::getStartDirectionIndex() const
 {
     return 2;
 }