diff --git a/src/build/opcode/test.rs b/src/build/opcode/test.rs
index 3740824..c16e360 100644
--- a/src/build/opcode/test.rs
+++ b/src/build/opcode/test.rs
@@ -559,3 +559,11 @@ fn simple_binary_expr() {
         //"true && false;" => P(Bool(false)),
     )
 }
+
+#[test]
+fn simple_not_expr() {
+    assert_parse_cases!(
+        "not 1==1;" => P(Bool(false)),
+        "not 1!=1;" => P(Bool(true)),
+    )
+}
diff --git a/src/build/opcode/translate.rs b/src/build/opcode/translate.rs
index 783ac02..bc9b206 100644
--- a/src/build/opcode/translate.rs
+++ b/src/build/opcode/translate.rs
@@ -105,7 +105,10 @@ impl AST {
             Expression::Import(_) => unimplemented!("Import expressions are not implmented yet"),
             Expression::Include(_) => unimplemented!("Include expressions are not implmented yet"),
             Expression::Module(_) => unimplemented!("Module expressions are not implmented yet"),
-            Expression::Not(_) => unimplemented!("Not expressions are not implmented yet"),
+            Expression::Not(def) => {
+                Self::translate_expr(*def.expr, &mut ops);
+                ops.push(Op::Not);
+            }
             Expression::Range(_) => unimplemented!("Range expressions are not implmented yet"),
             Expression::Select(_) => unimplemented!("Select expressions are not implmented yet"),
             Expression::Call(_) => unimplemented!("Call expressions are not implmented yet"),