diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 2793cf353a..a2e5b9b2f3 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -12,7 +12,7 @@ DEF_HELPER_FLAGS_3(divs32, TCG_CALL_NO_WG, s64, env, s64, s64)
 DEF_HELPER_FLAGS_3(divu32, TCG_CALL_NO_WG, i64, env, i64, i64)
 DEF_HELPER_FLAGS_3(divs64, TCG_CALL_NO_WG, s64, env, s64, s64)
 DEF_HELPER_FLAGS_4(divu64, TCG_CALL_NO_WG, i64, env, i64, i64, i64)
-DEF_HELPER_4(srst, i64, env, i64, i64, i64)
+DEF_HELPER_3(srst, void, env, i32, i32)
 DEF_HELPER_4(clst, i64, env, i64, i64, i64)
 DEF_HELPER_FLAGS_4(mvn, TCG_CALL_NO_WG, void, env, i32, i64, i64)
 DEF_HELPER_FLAGS_4(mvo, TCG_CALL_NO_WG, void, env, i32, i64, i64)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index 323a301d80..bc6ff01ad2 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -736,7 +736,7 @@
     C(0xec57, RXSBG,   RIE_f, GIE, 0, r2, r1, 0, rosbg, 0)
 
 /* SEARCH STRING */
-    C(0xb25e, SRST,    RRE,   Z,   r1_o, r2_o, 0, 0, srst, 0)
+    C(0xb25e, SRST,    RRE,   Z,   0, 0, 0, 0, srst, 0)
 
 /* SET ACCESS */
     C(0xb24e, SAR,     RRE,   Z,   0, r2_o, 0, 0, sar, 0)
diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
index 33e2694c03..2e3941f0c6 100644
--- a/target/s390x/mem_helper.c
+++ b/target/s390x/mem_helper.c
@@ -538,18 +538,21 @@ static inline void set_length(CPUS390XState *env, int reg, uint64_t length)
 }
 
 /* search string (c is byte to search, r2 is string, r1 end of string) */
-uint64_t HELPER(srst)(CPUS390XState *env, uint64_t r0, uint64_t end,
-                      uint64_t str)
+void HELPER(srst)(CPUS390XState *env, uint32_t r1, uint32_t r2)
 {
     uintptr_t ra = GETPC();
+    uint64_t end, str;
     uint32_t len;
-    uint8_t v, c = r0;
+    uint8_t v, c = env->regs[0];
 
-    str = wrap_address(env, str);
-    end = wrap_address(env, end);
+    /* Bits 32-55 must contain all 0.  */
+    if (env->regs[0] & 0xffffff00u) {
+        cpu_restore_state(ENV_GET_CPU(env), ra);
+        program_interrupt(env, PGM_SPECIFICATION, 6);
+    }
 
-    /* Assume for now that R2 is unmodified.  */
-    env->retxl = str;
+    str = get_address(env, r2);
+    end = get_address(env, r1);
 
     /* Lest we fail to service interrupts in a timely manner, limit the
        amount of work we're willing to do.  For now, let's cap at 8k.  */
@@ -557,20 +560,20 @@ uint64_t HELPER(srst)(CPUS390XState *env, uint64_t r0, uint64_t end,
         if (str + len == end) {
             /* Character not found.  R1 & R2 are unmodified.  */
             env->cc_op = 2;
-            return end;
+            return;
         }
         v = cpu_ldub_data_ra(env, str + len, ra);
         if (v == c) {
             /* Character found.  Set R1 to the location; R2 is unmodified.  */
             env->cc_op = 1;
-            return str + len;
+            set_address(env, r1, str + len);
+            return;
         }
     }
 
     /* CPU-determined bytes processed.  Advance R2 to next byte to process.  */
-    env->retxl = str + len;
     env->cc_op = 3;
-    return end;
+    set_address(env, r2, str + len);
 }
 
 /* unsigned string compare (c is string terminator) */
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index edfdaf40f3..e37a56fc85 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -4287,9 +4287,14 @@ static ExitStatus op_stpq(DisasContext *s, DisasOps *o)
 
 static ExitStatus op_srst(DisasContext *s, DisasOps *o)
 {
-    gen_helper_srst(o->in1, cpu_env, regs[0], o->in1, o->in2);
+    TCGv_i32 r1 = tcg_const_i32(get_field(s->fields, r1));
+    TCGv_i32 r2 = tcg_const_i32(get_field(s->fields, r2));
+
+    gen_helper_srst(cpu_env, r1, r2);
+
+    tcg_temp_free_i32(r1);
+    tcg_temp_free_i32(r2);
     set_cc_static(s);
-    return_low128(o->in2);
     return NO_EXIT;
 }