diff --git a/src/TR.jl b/src/TR.jl
index f005cba..0abfa2c 100644
--- a/src/TR.jl
+++ b/src/TR.jl
@@ -76,7 +76,7 @@ elseif regType == "GL" # Grünwald-Letnikov fractional derivative regulariztion
     # regParam1 is alpha (order of fractional derivative)
     C = ones(p)*1.0;
     for k in 2:p
-        C[k] = (-1)^(k-1) * (1-(regParam1+1)/k) * C[k-1];
+        C[k] = (1-(regParam1+1)/(k-1)) * C[k-1];
     end
 
     regMat = zeros(p,p);