diff --git a/target-s390x/helper.h b/target-s390x/helper.h
index 8e90741d3f6c5fe23e52ef6bee8d6b33d09942f6..3591a92adad1e4e4999384064c8490ecce4717d3 100644
--- a/target-s390x/helper.h
+++ b/target-s390x/helper.h
@@ -84,7 +84,6 @@ DEF_HELPER_3(servc, i32, env, i32, i64)
 DEF_HELPER_4(diag, i64, env, i32, i64, i64)
 DEF_HELPER_3(load_psw, void, env, i64, i64)
 DEF_HELPER_FLAGS_2(spx, TCG_CALL_NO_RWG, void, env, i64)
-DEF_HELPER_FLAGS_1(sck, TCG_CALL_NO_RWG, i32, i64)
 DEF_HELPER_2(stck, i32, env, i64)
 DEF_HELPER_2(stcke, i32, env, i64)
 DEF_HELPER_FLAGS_2(sckc, TCG_CALL_NO_RWG, void, env, i64)
diff --git a/target-s390x/insn-data.def b/target-s390x/insn-data.def
index 4d9ecf4b13f58b8b8119f1f9c8b7009bb31442c5..824e9dc526552c5adb90f6be85c708ec6ae04ffb 100644
--- a/target-s390x/insn-data.def
+++ b/target-s390x/insn-data.def
@@ -633,6 +633,9 @@
     /* We only do 64-bit, so accept this as a no-op.
        Let SAM24 and SAM31 signal illegal instruction.  */
     C(0x010e, SAM64,   E,     Z,   0, 0, 0, 0, 0, 0)
+/* SET CLOCK */
+    /* ??? Not implemented - is it necessary? */
+    C(0xb204, SCK,     S,     Z,   0, 0, 0, 0, 0, 0)
 /* SET SYSTEM MASK */
     C(0x8000, SSM,     S,     Z,   0, m2_8u, 0, 0, ssm, 0)
 /* SIGNAL PROCESSOR */
diff --git a/target-s390x/misc_helper.c b/target-s390x/misc_helper.c
index 009cc926609ca47b557389128f3eab71eb37487e..c16359134aa36d51684b23efad5fa0f9b042ee76 100644
--- a/target-s390x/misc_helper.c
+++ b/target-s390x/misc_helper.c
@@ -143,14 +143,6 @@ void HELPER(spx)(CPUS390XState *env, uint64_t a1)
     tlb_flush_page(env, TARGET_PAGE_SIZE);
 }
 
-/* Set Clock */
-uint32_t HELPER(sck)(uint64_t a1)
-{
-    /* XXX not implemented - is it necessary? */
-
-    return 0;
-}
-
 static inline uint64_t clock_value(CPUS390XState *env)
 {
     uint64_t time;
diff --git a/target-s390x/translate.c b/target-s390x/translate.c
index d57c737fc8fc223f957de888f4c4f94644b92790..e835df0ce979fcc37033bf385d855b3665497124 100644
--- a/target-s390x/translate.c
+++ b/target-s390x/translate.c
@@ -1033,16 +1033,6 @@ static void disas_b2(CPUS390XState *env, DisasContext *s, int op,
     LOG_DISAS("disas_b2: op 0x%x r1 %d r2 %d\n", op, r1, r2);
 
     switch (op) {
-    case 0x04: /* SCK       D2(B2)     [S] */
-        /* Set Clock */
-        check_privileged(s);
-        decode_rs(s, insn, &r1, &r3, &b2, &d2);
-        tmp = get_address(s, 0, b2, d2);
-        potential_page_fault(s);
-        gen_helper_sck(cc_op, tmp);
-        set_cc_static(s);
-        tcg_temp_free_i64(tmp);
-        break;
     case 0x05: /* STCK     D2(B2)     [S] */
         /* Store Clock */
         decode_rs(s, insn, &r1, &r3, &b2, &d2);