Index: BucketTemplate.c
===================================================================
--- BucketTemplate.c	(revision 30993)
+++ BucketTemplate.c	(working copy)
@@ -682,7 +682,7 @@
 Bucket_maxminKey(Bucket *self, PyObject *args, int min)
 {
   PyObject *key=0;
-  int rc, offset;
+  int rc, offset, empty_bucket = 1;
 
   if (args && ! PyArg_ParseTuple(args, "|O", &key)) return NULL;
 
@@ -696,6 +696,7 @@
       if ((rc = Bucket_findRangeEnd(self, key, min, 0, &offset)) <= 0)
         {
           if (rc < 0) return NULL;
+          empty_bucket = 0;
           goto empty;
         }
     }
@@ -708,7 +709,10 @@
   return key;
 
  empty:
-  PyErr_SetString(PyExc_ValueError, "empty bucket");
+  if (empty_bucket)
+    PyErr_SetString(PyExc_ValueError, "empty bucket");
+  else
+    PyErr_SetString(PyExc_ValueError, "doesn't exist any key satisfying the conditions");
   PER_UNUSE(self);
   return NULL;
 }
Index: tests/testBTrees.py
===================================================================
--- tests/testBTrees.py	(revision 30993)
+++ tests/testBTrees.py	(working copy)
@@ -301,6 +301,14 @@
         self.assertEqual(t.minKey(), 1)
         self.assertEqual(t.minKey(3), 3)
         self.assertEqual(t.minKey(9), 10)
+        try:
+            t.maxKey(t.minKey()-1)
+        except ValueError, err:
+            self.assertEqual(str(err), "doesn't exist any key satisfying the conditions")
+        try:
+            t.minKey(t.maxKey()+1)
+        except ValueError, err:
+            self.assertEqual(str(err), "doesn't exist any key satisfying the conditions")
 
     def testClear(self):
         r = range(100)
@@ -671,6 +679,14 @@
         self.assert_(t.minKey()-1 not in t)
         self.assert_(t.maxKey() in t)
         self.assert_(t.maxKey()+1 not in t)
+        try:
+            t.maxKey(t.minKey()-1)
+        except ValueError, err:
+            self.assertEqual(str(err), "doesn't exist any key satisfying the conditions")
+        try:
+            t.minKey(t.maxKey()+1)
+        except ValueError, err:
+            self.assertEqual(str(err), "doesn't exist any key satisfying the conditions")
 
     def testUpdate(self):
         d={}
Index: BTreeTemplate.c
===================================================================
--- BTreeTemplate.c	(revision 30993)
+++ BTreeTemplate.c	(working copy)
@@ -1340,7 +1340,7 @@
 {
   PyObject *key=0;
   Bucket *bucket = NULL;
-  int offset, rc;
+  int offset, rc, empty_tree = 1;
 
   UNLESS (PyArg_ParseTuple(args, "|O", &key)) return NULL;
 
@@ -1355,6 +1355,7 @@
       if ((rc = BTree_findRangeEnd(self, key, min, 0, &bucket, &offset)) <= 0)
         {
           if (rc < 0) goto err;
+          empty_tree = 0;
           goto empty;
         }
       PER_UNUSE(self);
@@ -1392,8 +1393,10 @@
   return key;
 
  empty:
-  PyErr_SetString(PyExc_ValueError, "empty tree");
-
+  if (empty_tree)
+    PyErr_SetString(PyExc_ValueError, "empty tree");
+  else
+    PyErr_SetString(PyExc_ValueError, "doesn't exist any key satisfying the conditions");
  err:
   PER_UNUSE(self);
   if (bucket)