diff --git a/contrib/plugins/lockstep.c b/contrib/plugins/lockstep.c
index 67a779ee9d..8b90b37f67 100644
--- a/contrib/plugins/lockstep.c
+++ b/contrib/plugins/lockstep.c
@@ -57,7 +57,7 @@ typedef struct {
 /* The execution state we compare */
 typedef struct {
     uint64_t pc;
-    unsigned long insn_count;
+    uint64_t insn_count;
 } ExecState;
 
 typedef struct {
@@ -148,7 +148,7 @@ static void report_divergance(ExecState *us, ExecState *them)
 
         g_string_printf(out,
                         "Δ insn_count @ 0x%016" PRIx64
-                        " (%ld) vs 0x%016" PRIx64 " (%ld)\n",
+                        " (%"PRId64") vs 0x%016" PRIx64 " (%"PRId64")\n",
                         us->pc, us->insn_count, them->pc, them->insn_count);
 
         for (entry = log, i = 0;