diff --git a/python/tvm/autotvm/task/space.py b/python/tvm/autotvm/task/space.py
index cf9cd809aa8d..afbfb4c03988 100644
--- a/python/tvm/autotvm/task/space.py
+++ b/python/tvm/autotvm/task/space.py
@@ -19,7 +19,7 @@
 """
 Template configuration space.
 
-Each template function can be parametrized by a ConfigSpace.
+Each template function can be parameterized by a ConfigSpace.
 The space is declared when we invoke the template function with ConfigSpace.
 During evaluation, we pass in a ConfigEntity, which contains a specific
 entity in the space. This entity contains deterministic parameters.
@@ -63,7 +63,7 @@ class TransformSpace(object):
         Each operator has some tunable parameters (e.g. the split factor).
         Then the tuning process is just to find good parameters of these op.
 
-    So the all the combinations of the parameters of these op forms our search space.
+    So all the combinations of the parameters of these op form our search space.
 
     Naming convention:
     We call the set of all possible values as XXXSpace. (XXX can be Split, Reorder, Config ...)
@@ -797,7 +797,7 @@ def add_flop(self, flop):
 
     def raise_error(self, msg):
         """register error in config
-        Using this to actively detect error when scheudling.
+        Using this to actively detect error when scheduling.
         Otherwise these error will occur during runtime, which
         will cost more time.
 
@@ -848,6 +848,8 @@ def get(self, index):
         index: int
             index in the space
         """
+        if index < 0 or index >= len(self):
+            raise IndexError("Index out of range: size {}, got index {}".format(len(self), index))
         entities = OrderedDict()
         t = index
         for name, space in self.space_map.items():
diff --git a/tests/python/unittest/test_autotvm_common.py b/tests/python/unittest/test_autotvm_common.py
index 917036fc24a1..60f7d8bafb1b 100644
--- a/tests/python/unittest/test_autotvm_common.py
+++ b/tests/python/unittest/test_autotvm_common.py
@@ -101,6 +101,6 @@ def get_sample_records(n):
 
     inps, ress = [], []
     for i in range(n):
-        inps.append(MeasureInput(target, tsk, tsk.config_space.get(i)))
+        inps.append(MeasureInput(target, tsk, tsk.config_space.get(i % len(tsk.config_space))))
         ress.append(MeasureResult((i + 1,), 0, i, time.time()))
     return list(zip(inps, ress))