diff --git a/Source/Utility/Math/Int64Math.cpp b/Source/Utility/Math/Int64Math.cpp
index 54e63286..a8228299 100644
--- a/Source/Utility/Math/Int64Math.cpp
+++ b/Source/Utility/Math/Int64Math.cpp
@@ -9,3 +9,13 @@ std::int64_t MaxInt64(const std::int64_t& first, const int& second) {
   }
   return first;
 }
+
+// OFFSET: 0x0086BF00
+// FUNCTION: fn_11017
+std::int64_t sub_86BF00(const int& value, const std::int64_t& other) {
+  const std::int64_t extended = value;
+  if (other < extended) {
+    return extended;
+  }
+  return other;
+}
diff --git a/Source/Utility/Math/Int64Math.h b/Source/Utility/Math/Int64Math.h
index f8900e1f..bf311843 100644
--- a/Source/Utility/Math/Int64Math.h
+++ b/Source/Utility/Math/Int64Math.h
@@ -4,5 +4,6 @@
 #include <cstdint>
 
 std::int64_t MaxInt64(const std::int64_t& first, const int& second);
+std::int64_t sub_86BF00(const int& value, const std::int64_t& other);
 
 #endif