diff --git a/math.d b/math.d
index a4b4d12..7f2c01f 100644
--- a/math.d
+++ b/math.d
@@ -10,7 +10,7 @@ import std.format;
 import std.stdio;
 
 T
-RoundUp(T a, T b)
+RoundUp(T)(T a, T b)
 {
 	a += b - 1;
 	a -= a%b;