diff --git a/eval_metrics.py b/eval_metrics.py
index 6d2f528..465f5e6 100644
--- a/eval_metrics.py
+++ b/eval_metrics.py
@@ -2,12 +2,15 @@ from __future__ import absolute_import
 import numpy as np
 import copy
 
-def evaluate(distmat, q_pids, g_pids, q_camids, g_camids):
-    num_q = distmat.shape[0]
+def evaluate(distmat, q_pids, g_pids, q_camids, g_camids, max_rank=50):
+    num_q, num_g = distmat.shape
+    if num_g < max_rank:
+        max_rank = num_g
+        print("Note: number of gallery samples is quite small, got {}".format(num_g))
     indices = np.argsort(distmat, axis=1)
     matches = (g_pids[indices] == q_pids[:, np.newaxis]).astype(np.int32)
 
-    # compute cmc curve for each query, maximum rank is fixed to _MAX_RANK
+    # compute cmc curve for each query
     all_cmc = []
     all_AP = []
     num_valid_q = 0.
@@ -30,7 +33,7 @@ def evaluate(distmat, q_pids, g_pids, q_camids, g_camids):
         cmc = cmc.cumsum()
         cmc[cmc > 1] = 1
 
-        all_cmc.append(cmc)
+        all_cmc.append(cmc[:max_rank])
         num_valid_q += 1.
 
         num_rel = cmc.sum()