diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c
index 68a4c60394..39ecf609a1 100644
--- a/tcg/s390/tcg-target.inc.c
+++ b/tcg/s390/tcg-target.inc.c
@@ -377,23 +377,29 @@ static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
 
     switch (type) {
     case R_390_PC16DBL:
-        assert(pcrel2 == (int16_t)pcrel2);
-        tcg_patch16(code_ptr, pcrel2);
+        if (pcrel2 == (int16_t)pcrel2) {
+            tcg_patch16(code_ptr, pcrel2);
+            return true;
+        }
         break;
     case R_390_PC32DBL:
-        assert(pcrel2 == (int32_t)pcrel2);
-        tcg_patch32(code_ptr, pcrel2);
+        if (pcrel2 == (int32_t)pcrel2) {
+            tcg_patch32(code_ptr, pcrel2);
+            return true;
+        }
         break;
     case R_390_20:
-        assert(value == sextract64(value, 0, 20));
-        old = *(uint32_t *)code_ptr & 0xf00000ff;
-        old |= ((value & 0xfff) << 16) | ((value & 0xff000) >> 4);
-        tcg_patch32(code_ptr, old);
+        if (value == sextract64(value, 0, 20)) {
+            old = *(uint32_t *)code_ptr & 0xf00000ff;
+            old |= ((value & 0xfff) << 16) | ((value & 0xff000) >> 4);
+            tcg_patch32(code_ptr, old);
+            return true;
+        }
         break;
     default:
         g_assert_not_reached();
     }
-    return true;
+    return false;
 }
 
 /* parse target specific constraints */
@@ -1334,6 +1340,7 @@ static void tgen_compare_branch(TCGContext *s, S390Opcode opc, int cc,
 
     if (l->has_value) {
         off = l->u.value_ptr - s->code_ptr;
+        tcg_debug_assert(off == (int16_t)off);
     } else {
         tcg_out_reloc(s, s->code_ptr + 1, R_390_PC16DBL, l, 2);
     }
@@ -1350,6 +1357,7 @@ static void tgen_compare_imm_branch(TCGContext *s, S390Opcode opc, int cc,
 
     if (l->has_value) {
         off = l->u.value_ptr - s->code_ptr;
+        tcg_debug_assert(off == (int16_t)off);
     } else {
         tcg_out_reloc(s, s->code_ptr + 1, R_390_PC16DBL, l, 2);
     }
@@ -1615,7 +1623,9 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOpIdx oi = lb->oi;
     TCGMemOp opc = get_memop(oi);
 
-    patch_reloc(lb->label_ptr[0], R_390_PC16DBL, (intptr_t)s->code_ptr, 2);
+    bool ok = patch_reloc(lb->label_ptr[0], R_390_PC16DBL,
+                          (intptr_t)s->code_ptr, 2);
+    tcg_debug_assert(ok);
 
     tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_R2, TCG_AREG0);
     if (TARGET_LONG_BITS == 64) {
@@ -1636,7 +1646,9 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *lb)
     TCGMemOpIdx oi = lb->oi;
     TCGMemOp opc = get_memop(oi);
 
-    patch_reloc(lb->label_ptr[0], R_390_PC16DBL, (intptr_t)s->code_ptr, 2);
+    bool ok = patch_reloc(lb->label_ptr[0], R_390_PC16DBL,
+                          (intptr_t)s->code_ptr, 2);
+    tcg_debug_assert(ok);
 
     tcg_out_mov(s, TCG_TYPE_PTR, TCG_REG_R2, TCG_AREG0);
     if (TARGET_LONG_BITS == 64) {