diff --git a/src/main/resources/META-INF/proguard/zt-zip.pro b/src/main/resources/META-INF/proguard/zt-zip.pro
new file mode 100644
index 0000000..ee8e783
--- /dev/null
+++ b/src/main/resources/META-INF/proguard/zt-zip.pro
@@ -0,0 +1,4 @@
+# make sure ZipExtraField constructors are kept
+-keep class * implements org.zeroturnaround.zip.extra.ZipExtraField {
+    public <init>();
+}