diff --git a/assembler/gram.c b/assembler/gram.c
index 8388d000..6b3ba475 100644
--- a/assembler/gram.c
+++ b/assembler/gram.c
@@ -979,7 +979,7 @@ case 52:
 {
 		  yyval.region.vert_stride = ffs(yyvsp[-5].integer);
 		  yyval.region.width = ffs(yyvsp[-3].integer) - 1;
-		  yyval.region.horiz_stride = ffs(yyvsp[-1].integer) - 1;
+		  yyval.region.horiz_stride = ffs(yyvsp[-1].integer);
 		}
 break;
 case 53:
diff --git a/assembler/gram.y b/assembler/gram.y
index 1e4192e7..913bfe8b 100644
--- a/assembler/gram.y
+++ b/assembler/gram.y
@@ -413,7 +413,7 @@ region:		LANGLE INTEGER COMMA INTEGER COMMA INTEGER RANGLE
 		{
 		  $$.vert_stride = ffs($2);
 		  $$.width = ffs($4) - 1;
-		  $$.horiz_stride = ffs($6) - 1;
+		  $$.horiz_stride = ffs($6);
 		}
 ;