diff --git a/include/matador/utils/constraints.hpp b/include/matador/utils/constraints.hpp
index e824d6d..247d0b9 100644
--- a/include/matador/utils/constraints.hpp
+++ b/include/matador/utils/constraints.hpp
@@ -5,13 +5,11 @@ namespace matador::utils {
 
 enum class constraints : unsigned char {
   NONE =        0,
-//  NOT_NULL =    1 << 0,
-  INDEX =       1 << 1,
-  UNIQUE =      1 << 2,
-  PRIMARY_KEY = 1 << 3,
-  FOREIGN_KEY = 1 << 4,
-  DEFAULT =     1 << 5
-//  UNIQUE_NOT_NULL = UNIQUE | NOT_NULL
+  INDEX =       1 << 0,
+  UNIQUE =      1 << 1,
+  PRIMARY_KEY = 1 << 2,
+  FOREIGN_KEY = 1 << 3,
+  DEFAULT =     1 << 4
 };
 
 inline constraints operator|(constraints a, constraints b) { return static_cast<constraints>(static_cast<unsigned int>(a) | static_cast<unsigned int>(b)); }