diff --git a/priv/host_s390_defs.c b/priv/host_s390_defs.c
index c17335a..432b985 100644
--- a/priv/host_s390_defs.c
+++ b/priv/host_s390_defs.c
@@ -6456,7 +6456,7 @@
 const HChar *
 s390_insn_as_string(const s390_insn *insn)
 {
-   static HChar buf[300];
+   static HChar buf[300];  // large enough
    const HChar *op;
    HChar *p;