diff --git a/stim/cuda/templates/gradient.cuh b/stim/cuda/templates/gradient.cuh
index 88dd259..febd57b 100644
--- a/stim/cuda/templates/gradient.cuh
+++ b/stim/cuda/templates/gradient.cuh
@@ -32,20 +32,16 @@ namespace stim{
 			//use forward differences if a coordinate is zero
 			if(xi == 0)
 				out[i * 2 + 0] = in[i_xp] - in[i];
-			if(yi == 0)
-				out[i * 2 + 1] = in[i_yp] - in[i];
-
-			//use backward differences if the coordinate is at the maximum edge
-			if(xi == x-1)
+			else if (xi == x - 1)
 				out[i * 2 + 0] = in[i] - in[i_xn];
-			if(yi == y-1)
-				out[i * 2 + 1] = in[i] - in[i_yn];
-
-			//otherwise use central differences
-			if(xi > 0 && xi < x-1)
+			else
 				out[i * 2 + 0] = (in[i_xp] - in[i_xn]) / 2;
 
-			if(yi > 0 && yi < y-1)
+			if(yi == 0)
+				out[i * 2 + 1] = in[i_yp] - in[i];
+			else if(yi == y-1)
+				out[i * 2 + 1] = in[i] - in[i_yn];
+			else
 				out[i * 2 + 1] = (in[i_yp] - in[i_yn]) / 2;
 
 		}
--
libgit2 0.21.4