diff --git a/src/image-load.c b/src/image-load.c
index 7c75f01f..a1118c68 100644
--- a/src/image-load.c
+++ b/src/image-load.c
@@ -1083,7 +1083,7 @@ static gboolean image_loader_setup_source(ImageLoader *il)
 			return FALSE;
 			}
 
-		il->mapped_file = mmap(0, il->bytes_total, PROT_READ|PROT_WRITE, MAP_PRIVATE, load_fd, 0);
+		il->mapped_file = mmap(0, il->bytes_total, PROT_READ, MAP_PRIVATE, load_fd, 0);
 		close(load_fd);
 		if (il->mapped_file == MAP_FAILED)
 			{