diff --git a/cml/ports/source_adapters.py b/cml/ports/source_adapters.py
index 3f01a432ee08687e81d6eddaf46512d698a305a7..d769fbc6a4e0238076a8a3e070e23fcbf38b27d4 100644
--- a/cml/ports/source_adapters.py
+++ b/cml/ports/source_adapters.py
@@ -54,16 +54,17 @@ class PandasBlock:
 
     def get_values(self, **kwargs):
         t, z, sigma = kwargs.get("T"), kwargs.get("Z"), kwargs.get("Sigma")
-        if t and z:
+
+        if t is not None and z is not None:
             data_frame = self.__data_block.loc[
                 (self.__data_block["T"] == t) & (self.__data_block["Z"] == z)]
 
-        elif t and sigma:
+        elif t is not None and sigma is not None:
             data_frame = self.__data_block.loc[
                 (self.__data_block["T"] == t) & (
                         self.__data_block["Sigma"] == sigma)]
 
-        elif z and sigma:
+        elif z is not None and sigma is not None:
             data_frame = self.__data_block.loc[
                 (self.__data_block["Z"] == z) & (
                         self.__data_block["Sigma"] == sigma)]