diff --git a/src/QueuePerThreadPool.c b/src/QueuePerThreadPool.c
index 38c25b03b..5de499620 100644
--- a/src/QueuePerThreadPool.c
+++ b/src/QueuePerThreadPool.c
@@ -118,6 +118,10 @@ struct QPTPool {
     #if defined(DEBUG) && defined(PER_THREAD_STATS)
     struct OutputBuffers *debug_buffers;
     #endif
+
+    #if defined(DEBUG) && defined(QPTPOOL_QUEUE_SIZE)
+    size_t queue_size_highwater;  /* used when printing out queue size stats */
+    #endif
 };
 
 /* struct to pass into pthread_create */
@@ -272,21 +276,32 @@ static void claim_work(QPTPoolThreadData_t *tw) {
 static void dump_queue_size_stats(QPTPool_t *ctx, QPTPoolThreadData_t *tw) {
     pthread_mutex_lock(&ctx->mutex);
     pthread_mutex_lock(&print_mutex);
-    tw->waiting.size = tw->claimed.size;
 
-    struct timespec now;
-    clock_gettime(CLOCK_MONOTONIC, &now);
-    fprintf(stderr, "qptpool_size %" PRIu64 " ", since_epoch(&now) - epoch);
+    if (ctx->incomplete) {
+        tw->waiting.size = tw->claimed.size;
 
-    size_t sum = 0;
-    for(size_t i = 0; i < ctx->nthreads; i++) {
-        fprintf(stderr, "%zu ", ctx->data[i].waiting.size);
-        sum += ctx->data[i].waiting.size;
-        fprintf(stderr, "%zu ", ctx->data[i].deferred.size);
-        sum += ctx->data[i].deferred.size;
+        char buf[4096];
+        size_t n = 0;
+
+        size_t sum = 0;
+        for(size_t i = 0; i < ctx->nthreads; i++) {
+            n += SNPRINTF(buf + n, sizeof(buf) - n, "%zu ", ctx->data[i].waiting.size);
+            sum += ctx->data[i].waiting.size;
+            n += SNPRINTF(buf + n, sizeof(buf) - n, "%zu ", ctx->data[i].deferred.size);
+            sum += ctx->data[i].deferred.size;
+        }
+
+        if (sum > ctx->queue_size_highwater) {
+            ctx->queue_size_highwater = sum;
+
+            struct timespec now;
+            clock_gettime(CLOCK_MONOTONIC, &now);
+            fprintf(stderr, "qptpool_size %" PRIu64 " %s total: %zu\n", since_epoch(&now) - epoch, buf, sum);
+        }
+
+        tw->waiting.size = 0;
     }
-    fprintf(stderr, "%zu\n", sum);
-    tw->waiting.size = 0;
+
     pthread_mutex_unlock(&print_mutex);
     pthread_mutex_unlock(&ctx->mutex);
 }
@@ -634,6 +649,10 @@ QPTPool_t *QPTPool_init_with_props(const size_t nthreads,
     ctx->debug_buffers = debug_buffers;
     #endif
 
+    #if defined(DEBUG) && defined(QPTPOOL_QUEUE_SIZE)
+    ctx->queue_size_highwater = 0;
+    #endif
+
     ctx->data = calloc(nthreads, sizeof(QPTPoolThreadData_t));
     if (!ctx->data) {
         free(ctx);