diff --git a/xz-java.spec b/xz-java.spec
index c951bf0..cba9d4b 100644
--- a/xz-java.spec
+++ b/xz-java.spec
@@ -31,19 +31,6 @@ for advanced users, including LZMA2 with preset dictionary.
 %prep
 %autosetup -p1 -C
 
-# Strip modern Ant namespace attributes for bootstrap compatibility.
-# javapackages-bootstrap uses an older Ant that doesn't support ant:if/ant:unless.
-# TODO Drop after javapackages-bootstrap > 1.27 is released
-sed -i 's/xmlns:if="ant:if"//g' build.xml
-sed -i 's/xmlns:unless="ant:unless"//g' build.xml
-sed -i 's/\sif:true="[^"]*"//g' build.xml
-sed -i 's/\sunless:true="[^"]*"//g' build.xml
-sed -i 's/\sif:set="[^"]*"//g' build.xml
-sed -i 's/\sunless:set="[^"]*"//g' build.xml
-sed -i 's/\smodificationtime="[^"]*"//g' build.xml
-sed -i 's/if:true="[^"]*"//g' build.xml
-sed -i 's/unless:true="[^"]*"//g' build.xml
-
 %mvn_file : %{name} xz
 
 %build