diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index a0e56c6241f..7d4d3d7c333 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -126,16 +126,13 @@ typedef struct Library {
 #define PREVIEW_MIPMAP_ZERO 0
 #define PREVIEW_MIPMAP_LARGE 1
 
-/* not saved, note 'PREVIEW_MIPMAPS' will break makesdna parsing.
- * replace with value if saving to blend files */
-#
-#
 typedef struct PreviewImage {
-	unsigned int w[PREVIEW_MIPMAPS];
-	unsigned int h[PREVIEW_MIPMAPS];
-	short changed[PREVIEW_MIPMAPS];
-	short changed_timestamp[PREVIEW_MIPMAPS];
-	unsigned int * rect[PREVIEW_MIPMAPS];
+	/* All values of 2 are really PREVIEW_MIPMAPS */
+	unsigned int w[2];
+	unsigned int h[2];
+	short changed[2];
+	short changed_timestamp[2];
+	unsigned int * rect[2];
 } PreviewImage;
 
 /**