diff --git a/VM/src/lmathlib.cpp b/VM/src/lmathlib.cpp
index 0693b846..1abbbbe6 100644
--- a/VM/src/lmathlib.cpp
+++ b/VM/src/lmathlib.cpp
@@ -300,10 +300,14 @@ static float fade(float t)
     return t * t * t * (t * (t * 6 - 15) + 10);
 }
 
+#ifdef __clang__
+#if __cplusplus <= 201703L
 static float lerp(float t, float a, float b)
 {
     return a + t * (b - a);
 }
+#endif
+#endif
 
 static float grad(unsigned char hash, float x, float y, float z)
 {