diff --git a/pysped/nfe/leiaute/nfe_110.py b/pysped/nfe/leiaute/nfe_110.py
index bc67412f..97b9fa7e 100644
--- a/pysped/nfe/leiaute/nfe_110.py
+++ b/pysped/nfe/leiaute/nfe_110.py
@@ -800,7 +800,7 @@ def __init__(self):
 
 
     def get_xml(self):
-        if self.CST.valor in ('01', '02', '03', '04', '51', '52', '53', '54', '55'):
+        if not self.CST.valor.strip():
             return ''
 
         #
diff --git a/pysped/nfe/leiaute/nfe_310.py b/pysped/nfe/leiaute/nfe_310.py
index c6fadfa7..e55f184f 100644
--- a/pysped/nfe/leiaute/nfe_310.py
+++ b/pysped/nfe/leiaute/nfe_310.py
@@ -392,7 +392,7 @@ def __init__(self):
         self.pIPI = TagDecimal(nome='pIPI', codigo='O13', tamanho=[1,  5, 1], decimais=[0, 4, 4], raiz='')
 
     def get_xml(self):
-        if self.CST.valor not in ('01', '02', '03', '04', '50', '51', '52', '53', '54', '55'):
+        if not self.CST.valor.strip():
             return ''
 
         #