diff --git a/.gitattributes b/.gitattributes
index 3d99a6b2..8873ffda 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2,3 +2,4 @@
 .gitignore export-ignore
 .mailmap export-ignore
 *.pdf -text -diff
+*.ppm -text -diff