diff --git a/.gitattributes b/.gitattributes
index b3e2769d6..bfc1cfb05 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -13,3 +13,4 @@
 
 *.tga binary diff=hex
 *.kra binary diff=hex
+*.btexbin binary diff=hex
diff --git a/src/net/torvald/terrarum/tests/BTeXTest.kt b/src/net/torvald/terrarum/tests/BTeXTest.kt
index 2869c5466..42b8a3416 100644
--- a/src/net/torvald/terrarum/tests/BTeXTest.kt
+++ b/src/net/torvald/terrarum/tests/BTeXTest.kt
@@ -63,7 +63,7 @@ class BTeXTest : ApplicationAdapter() {
         }
 
         measureTimeMillis {
-            document.serialise(File("./assets/mods/basegame/books/${filePath.replace(".xml", ".book")}"))
+            document.serialise(File("./assets/mods/basegame/books/${filePath.replace(".xml", ".btexbin")}"))
         }.also {
             println("Time spent on serialisation [ms]: $it")
         }