diff --git a/g2gtools/__init__.py b/g2gtools/__init__.py
index f6b15fe..9191094 100644
--- a/g2gtools/__init__.py
+++ b/g2gtools/__init__.py
@@ -14,7 +14,7 @@
 from .bins import bins
 
 
-__version__ = '0.1.18'
+__version__ = '0.1.19'
 __author__ = 'Matthew Vincent, The Jackson Laboratory'
 __email__ = 'matt.vincent@jax.org'
 
diff --git a/g2gtools/vcf.py b/g2gtools/vcf.py
index 5217311..e35fa6d 100644
--- a/g2gtools/vcf.py
+++ b/g2gtools/vcf.py
@@ -137,7 +137,7 @@ def parse_gt(vcf_record, sample_index):
     :type sample_index: int
     :return: :class:`.vcf.GTData`
     """
-    if not sample_index:
+    if sample_index is None:
         raise G2GVCFError("Sample index must contain a value")
 
     sample_data = vcf_record.SAMPLES[sample_index]
@@ -201,7 +201,7 @@ def parse_gt_new(vcf_tuple, sample_index):
     :type sample_index: int
     :return: :class:`.vcf.GTData`
     """
-    if not sample_index:
+    if sample_index is None:
         raise G2GVCFError("Sample index must contain a value")
 
     sample_data = vcf_tuple[sample_index]
diff --git a/setup.py b/setup.py
index 7535228..f3d72f2 100755
--- a/setup.py
+++ b/setup.py
@@ -73,7 +73,7 @@ def main():
 
     setup(
         name='g2gtools',
-        version='v0.1.18',
+        version='v0.1.19',
         description="A set of tools that facilitates genome to genome conversion for studying multiparent populations",
         long_description=readme + '\n\n' + history,
         author='Kwangbom "KB" Choi & Matthew Vincent, The Jackson Laboratory',