diff --git a/CHANGES.md b/CHANGES.md
index a0415cb..a600215 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,6 @@
+# v0.30.15
++ fix num_unknown when gts012=True (#236)
+
 # v0.30.14
 + use warnings instead of sys.stderr (#229 from @grahamgower)
 + use libdeflate in wheel build (#231 from @grahamgower)
diff --git a/cyvcf2/__init__.py b/cyvcf2/__init__.py
index 497aa08..2f0119d 100644
--- a/cyvcf2/__init__.py
+++ b/cyvcf2/__init__.py
@@ -2,4 +2,4 @@
                      par_het)
 Reader = VCFReader = VCF
 
-__version__ = "0.30.14"
+__version__ = "0.30.15"
diff --git a/cyvcf2/cyvcf2.pyx b/cyvcf2/cyvcf2.pyx
index 9baa6bf..ba49a38 100644
--- a/cyvcf2/cyvcf2.pyx
+++ b/cyvcf2/cyvcf2.pyx
@@ -1274,9 +1274,9 @@ cdef class Variant(object):
             if self._gt_types == NULL:
                 self.gt_types
             cdef int n = 0, i = 0
+            cdef int unknown = 3 if self.vcf.gts012 else 2
             for i in range(self.vcf.n_samples):
-                if self._gt_types[i] == 2:
-                    n+=1
+                n += (self._gt_types[i] == unknown)
             return n
 
     property FORMAT:
diff --git a/cyvcf2/tests/test_reader.py b/cyvcf2/tests/test_reader.py
index 3d8e81e..8d41af7 100644
--- a/cyvcf2/tests/test_reader.py
+++ b/cyvcf2/tests/test_reader.py
@@ -1302,3 +1302,17 @@ def test_genotypes():
             a = v.genotype.array()[0] # only 0'th item
             print("i:", i, " a:", v.genotype.array()[0], " exp:", exp_array[i])
             assert (a == exp_array[i]).all(), " error with array"
+
+def test_issue236():
+
+
+    for strict_gt in (False, True):
+        res = [[], []]
+
+        for gts in (False, True):
+            vcf = VCF(os.path.join(HERE, "test-genotypes.vcf"), gts012=gts, strict_gt=strict_gt)
+            for v in vcf:
+                res[int(gts)].append(v.num_unknown)
+
+        assert res[0] == res[1]
+        assert len(res[0]) > 0