German word lemmas

When adding a German word with “zu” infinitive, it does not lemmatize it properly (for example, “einzujagen” should be added as “einjagen”). Basically, it treats zu-infinitive as a true infinitive of the word, especially with verbs that have a separable prefix (perhaps with other words too, with no prefix, and with non-separable prefixes, but I did not come across those yet, probably).