diff --git a/basis/opengl/opengl.factor b/basis/opengl/opengl.factor
index 8e9cd3a3b8..aec7960857 100644
--- a/basis/opengl/opengl.factor
+++ b/basis/opengl/opengl.factor
@@ -72,9 +72,9 @@ MACRO: all-enabled-client-state ( seq quot -- )
 : (rect-vertices) ( dim -- vertices )
     {
         [ drop 0.5 0.5 ]
-        [ first 0.5 ]
-        [ [ first ] [ second ] bi ]
-        [ second 0.5 swap ]
+        [ first 0.5 - 0.5 ]
+        [ [ first 0.5 - ] [ second 0.5 - ] bi ]
+        [ second 0.5 - 0.5 swap ]
     } cleave 8 narray >c-float-array ;
 
 : rect-vertices ( dim -- )
diff --git a/basis/ui/gadgets/grid-lines/grid-lines.factor b/basis/ui/gadgets/grid-lines/grid-lines.factor
index 0356e7fd4d..d7844e3fa3 100644
--- a/basis/ui/gadgets/grid-lines/grid-lines.factor
+++ b/basis/ui/gadgets/grid-lines/grid-lines.factor
@@ -27,6 +27,9 @@ M: grid-lines draw-boundary
         dup grid set
         dup rect-dim half-gap v- grid-dim set
         compute-grid
-        { 0 1 } draw-grid-lines
-        { 1 0 } draw-grid-lines
+        [ { 1 0 } draw-grid-lines ]
+        [
+            { 0.5 -0.5 } gl-translate
+            { 0 1 } draw-grid-lines
+        ] bi*
     ] with-scope ;