diff --git a/pysam/libcalignedsegment.pyx b/pysam/libcalignedsegment.pyx
index c9c27734..3afcf006 100644
--- a/pysam/libcalignedsegment.pyx
+++ b/pysam/libcalignedsegment.pyx
@@ -75,6 +75,7 @@ from pysam.libcutils cimport force_bytes, force_str, \
     charptr_to_str, charptr_to_bytes
 from pysam.libcutils cimport qualities_to_qualitystring, qualitystring_to_array, \
     array_to_qualitystring
+from libc.stdio cimport snprintf
 
 # Constants for binary tag conversion
 cdef char * htslib_types = 'cCsSiIf'
@@ -1313,12 +1314,38 @@ cdef class AlignedSegment:
         empty string.
         '''
         def __get__(self):
-            c = self.cigartuples
-            if c is None:
+            cdef uint32_t *cigar_p
+            cdef bam1_t *src
+            cdef uint32_t op, l
+            cdef int k
+            cdef int ret
+            cdef int pos = 0
+            cdef int size = 16
+            cdef kstring_t buf
+            buf.l = buf.m = 0
+            buf.s = NULL
+
+            src = self._delegate
+            if pysam_get_n_cigar(src) == 0:
                 return None
-            # reverse order
-            else:
-                return "".join([ "%i%c" % (y,CODE2CIGAR[x]) for x,y in c])
+
+            cigar_p = pysam_bam_get_cigar(src)
+            while True:
+                for k from 0 <= k < pysam_get_n_cigar(src):
+                    op = cigar_p[k] & BAM_CIGAR_MASK
+                    l = cigar_p[k] >> BAM_CIGAR_SHIFT
+                    kputl(l, &buf)
+                    kputc(<int>(CODE2CIGAR[op]), &buf)
+                else:
+                    break
+
+            try:
+                return buf.s[:buf.l].decode("utf8")
+            finally:
+                if buf.m:
+                    free(buf.s)
+
+            return ret
 
         def __set__(self, cigar):
             if cigar is None or len(cigar) == 0:
diff --git a/tests/AlignedSegment_test.py b/tests/AlignedSegment_test.py
index af0e270b..f7df083d 100644
--- a/tests/AlignedSegment_test.py
+++ b/tests/AlignedSegment_test.py
@@ -992,6 +992,16 @@ def testStats(self):
             expected[1][i] = 1
             self.assertEqual([list(x) for x in a.get_cigar_stats()], expected)
 
+        for i in range(1, 100):
+            cigarstring = "".join("10{}".format(x)
+                                  for x in iter("MIDNSHP=X")) * i
+            a.cigarstring = cigarstring
+            self.assertEqual(a.cigarstring, cigarstring)
+            expected = [[i * 10 for j in range(len("MIDNSHP=X"))] + [0, 0],
+                        [i for j in range(len("MIDNSHP=X"))] + [0, 0]]
+            obtained = [list(x) for x in a.get_cigar_stats()]
+            self.assertEqual(obtained, expected)
+
         a.cigarstring = "10M"
         a.set_tag("NM", 5)
         self.assertEqual(