diff --git a/centvrion/ast_nodes.py b/centvrion/ast_nodes.py
index 723596c..2439fe0 100644
--- a/centvrion/ast_nodes.py
+++ b/centvrion/ast_nodes.py
@@ -462,6 +462,24 @@ class UnaryMinus(Node):
     return vtable, ValInt(-val.value())
 
 
+class UnaryNot(Node):
+  def __init__(self, expr):
+    self.expr = expr
+
+  def __eq__(self, other):
+    return type(self) == type(other) and self.expr == other.expr
+
+  def __repr__(self):
+    return f"UnaryNot({self.expr!r})"
+
+  def print(self):
+    return f"(NON {self.expr.print()})"
+
+  def _eval(self, vtable):
+    vtable, val = self.expr.eval(vtable)
+    return vtable, ValBool(not bool(val))
+
+
 class ArrayIndex(Node):
   def __init__(self, array, index) -> None:
     self.array = array
diff --git a/centvrion/lexer.py b/centvrion/lexer.py
index b6258c9..21b3ff7 100644
--- a/centvrion/lexer.py
+++ b/centvrion/lexer.py
@@ -17,6 +17,7 @@ keyword_tokens = [("KEYWORD_"+i, i) for i in [
   "INVOCA",
   "IN",
   "MINVS",
+  "NON",
   "NVLLVS",
   "PER",
   "PLVS",
diff --git a/centvrion/parser.py b/centvrion/parser.py
index 63bac9b..3ead9e5 100644
--- a/centvrion/parser.py
+++ b/centvrion/parser.py
@@ -15,7 +15,7 @@ class Parser():
         ('left', ["KEYWORD_PLVS", "KEYWORD_MINVS", "KEYWORD_EST"]),
         ('left', ["SYMBOL_COLON", "SYMBOL_PLUS", "SYMBOL_MINUS"]),
         ('left', ["SYMBOL_TIMES", "SYMBOL_DIVIDE"]),
-        ('right', ["UMINUS"]),
+        ('right', ["UMINUS", "UNOT"]),
         ('left', ["INDEX"]),
       ]
     )
@@ -191,6 +191,10 @@ class Parser():
     def unary_minus(tokens):
       return ast_nodes.UnaryMinus(tokens[1])
 
+    @self.pg.production('expression : KEYWORD_NON expression', precedence='UNOT')
+    def unary_not(tokens):
+      return ast_nodes.UnaryNot(tokens[1])
+
     @self.pg.production('expression : KEYWORD_INVOCA id expressions')
     def invoca(tokens):
       return ast_nodes.Invoca(tokens[1], tokens[2])
diff --git a/tests.py b/tests.py
index b76dde3..6605d6c 100644
--- a/tests.py
+++ b/tests.py
@@ -8,7 +8,7 @@ from centvrion.ast_nodes import (
   ArrayIndex, Bool, BinOp, BuiltIn, DataArray, DataRangeArray, Defini,
   Designa, DumStatement, Erumpe, ExpressionStatement, ID,
   Invoca, ModuleCall, Nullus, Numeral, PerStatement,
-  Program, Redi, SiStatement, String, UnaryMinus,
+  Program, Redi, SiStatement, String, UnaryMinus, UnaryNot,
   num_to_int, int_to_num, make_string,
 )
 from centvrion.lexer import Lexer
@@ -160,6 +160,10 @@ precedence_tests = [
   ("CVM SVBNVLLA\n- [I, II, III][I]",
     Program([ModuleCall("SVBNVLLA")], [ExpressionStatement(UnaryMinus(ArrayIndex(DataArray([Numeral("I"), Numeral("II"), Numeral("III")]), Numeral("I"))))]),
     ValInt(-1)),
+  # INDEX binds tighter than NON: NON (arr[I]) = NON VERITAS = False
+  ("NON [VERITAS, FALSITAS][I]",
+    Program([], [ExpressionStatement(UnaryNot(ArrayIndex(DataArray([Bool(True), Bool(False)]), Numeral("I"))))]),
+    ValBool(False)),
   # INDEX binds tighter than +: (arr[II]) + X = 2 + 10 = 12
   ("[I, II, III][II] + X",
     Program([], [ExpressionStatement(BinOp(ArrayIndex(DataArray([Numeral("I"), Numeral("II"), Numeral("III")]), Numeral("II")), Numeral("X"), "SYMBOL_PLUS"))]),
@@ -1080,5 +1084,40 @@ class TestScope(unittest.TestCase):
     run_test(self, source, nodes, value)
 
 
+# --- NON (boolean not) ---
+
+non_tests = [
+  ("NON VERITAS",
+    Program([], [ExpressionStatement(UnaryNot(Bool(True)))]),
+    ValBool(False)),
+  ("NON FALSITAS",
+    Program([], [ExpressionStatement(UnaryNot(Bool(False)))]),
+    ValBool(True)),
+  ("NON NON VERITAS",
+    Program([], [ExpressionStatement(UnaryNot(UnaryNot(Bool(True))))]),
+    ValBool(True)),
+  ("NON I",
+    Program([], [ExpressionStatement(UnaryNot(Numeral("I")))]),
+    ValBool(False)),
+  # zero int is falsy, so NON gives True
+  ("DESIGNA z VT I - I\nNON z",
+    Program([], [Designa(ID("z"), BinOp(Numeral("I"), Numeral("I"), "SYMBOL_MINUS")), ExpressionStatement(UnaryNot(ID("z")))]),
+    ValBool(True)),
+  # NON binds tighter than AVT: (NON VERITAS) AVT FALSITAS → FALSITAS AVT FALSITAS → False
+  ("NON VERITAS AVT FALSITAS",
+    Program([], [ExpressionStatement(BinOp(UnaryNot(Bool(True)), Bool(False), "KEYWORD_AVT"))]),
+    ValBool(False)),
+  # NON binds tighter than EST: (NON I) EST I → FALSITAS EST I → False
+  ("NON I EST I",
+    Program([], [ExpressionStatement(BinOp(UnaryNot(Numeral("I")), Numeral("I"), "KEYWORD_EST"))]),
+    ValBool(False)),
+]
+
+class TestNon(unittest.TestCase):
+  @parameterized.expand(non_tests)
+  def test_non(self, source, nodes, value):
+    run_test(self, source, nodes, value)
+
+
 if __name__ == "__main__":
   unittest.main()