diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index 4e51cf8..a0c740e 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -403,10 +403,9 @@
 #if defined(TARGET_AVR) || defined(TARGET_HEXAGON) \
     || defined(TARGET_RISCV) || defined(TARGET_SH4) \
     || defined(TARGET_TRICORE) || defined(TARGET_ARM) || defined(TARGET_MIPS) \
-    || defined(TARGET_LOONGARCH64) || defined(TARGET_HPPA)
+    || defined(TARGET_LOONGARCH64) || defined(TARGET_HPPA) \
+    || defined(TARGET_S390X)
         g_assert_not_reached();
-#elif defined(TARGET_S390X)
-        rule = float_2nan_prop_s_ab;
 #elif defined(TARGET_PPC) || defined(TARGET_M68K)
         /*
          * PowerPC propagation rules:
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index 4e41a3d..514c70f 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -205,6 +205,7 @@
         /* tininess for underflow is detected before rounding */
         set_float_detect_tininess(float_tininess_before_rounding,
                                   &env->fpu_status);
+        set_float_2nan_prop_rule(float_2nan_prop_s_ab, &env->fpu_status);
        /* fall through */
     case RESET_TYPE_S390_CPU_NORMAL:
         env->psw.mask &= ~PSW_MASK_RI;