æz ɐ ɹɪzˈʌlt, hˈɛklɚ ænd kˈɑːk mˈɑːdᵻfˌaɪd ðə wˈɛpən wɪð ɐ plˈeɪt wˈɛldᵻd ɪnsˈaɪd ðə ɹᵻsˈiːvɚ tə pɹɪvˈɛnt ðə mˈaʊntɪŋ əvə fˈʊlˈɔːɾoʊ "sˈɛf" fˈaɪɚ kəntɹˈoʊl ɡɹˈuːp ænd ɹˌiːdˈɛzɪɡnˌeɪɾᵻd ðə ɹˈaɪfəl æz ðə hˈɛklɚ ænd kˈɑːk ˌeɪtʃkˈeɪ nˈaɪnti wˈʌn.
As a result, Heckler & Koch modified the weapon with a plate welded inside the receiver to prevent the mounting of a full-auto "SEF" fire control group and re-designated the rifle as the Heckler & Koch HK91.