diff --git a/internal/atlas/export_test.go b/internal/atlas/export_test.go
index 0d112d37d..d647af2f6 100644
--- a/internal/atlas/export_test.go
+++ b/internal/atlas/export_test.go
@@ -16,6 +16,7 @@ package atlas
 
 const (
 	BaseCountToPutOnAtlas = baseCountToPutOnAtlas
+	PaddingSize           = paddingSize
 )
 
 func PutImagesOnAtlasForTesting() error {
diff --git a/internal/atlas/image_test.go b/internal/atlas/image_test.go
index dc84c936e..9bc063c57 100644
--- a/internal/atlas/image_test.go
+++ b/internal/atlas/image_test.go
@@ -522,7 +522,7 @@ func TestExtendWithBigImage(t *testing.T) {
 // Issue #1217
 func TestMaxImageSize(t *testing.T) {
 	// This tests that a too-big image is allocated correctly.
-	s := maxImageSizeForTesting
+	s := maxImageSizeForTesting - 2*PaddingSize
 	img := NewImage(s, s)
 	defer img.MarkDisposed()
 	img.ReplacePixels(make([]byte, 4*s*s))