I'm still able to reproduce with Proguard 5.3.3 and the attached project. The problematic signature is "Lp/a<TT;>.p/b<TV;>;" you can reproduce with javac p/*.java jar cvf ../generic.jar . proguard.sh -injars ../generic.jar -outjars ../proguarded.jar @p/proguard.flags -libraryjars $JAVA_HOME/jre/lib/rt.jar java -cp ../proguarded.jar p.Main Tested to fail on java 1.8.0_45 with Exception in thread "main" java.lang.reflect.GenericSignatureFormatError: Signature Parse error: expected '<' or ';' or '.',...