diff --git a/client/src/cmddata.c b/client/src/cmddata.c
index 5a6d897e3c..e244a7bf52 100644
--- a/client/src/cmddata.c
+++ b/client/src/cmddata.c
@@ -862,7 +862,7 @@ int AutoCorrelate(const int *in, int *out, size_t len, size_t window, bool SaveG
     int distance = -1;
     for (size_t i = 0; i < ARRAYLEN(peaks); ++i) {
 
-        PrintAndLogEx(DEBUG, "%zu | %d", i, peaks[i]);
+        PrintAndLogEx(DEBUG, "%zu | %zu", i, peaks[i]);
         if (peaks[i] < 128) {
             continue;
         }