diff --git a/target/hppa/int_helper.c b/target/hppa/int_helper.c
index 58695def82..d87e5a5a34 100644
--- a/target/hppa/int_helper.c
+++ b/target/hppa/int_helper.c
@@ -175,6 +175,10 @@ void hppa_cpu_do_interrupt(CPUState *cs)
                     }
                 }
                 env->cr[CR_IIR] = ldl_phys(cs->as, paddr);
+                if (i == EXCP_ASSIST) {
+                    /* stuff insn code into bits of FP exception register #1 */
+                    env->fr[0] |= (env->cr[CR_IIR] & 0x03ffffff);
+                }
             }
             break;