diff --git a/integration/tests/cookies.hurl b/integration/tests/cookies.hurl
index 21543ae9a..4767e333f 100644
--- a/integration/tests/cookies.hurl
+++ b/integration/tests/cookies.hurl
@@ -64,8 +64,8 @@ cookie "LSID[Expires]" equals "Wed, 13 Jan 2021 22:23:01 GMT"
 cookie "LSID[Max-Age]" not exists
 cookie "LSID[Domain]" not exists
 cookie "LSID[Path]" equals "/accounts"
-cookie "LSID[Secure]" equals true
-cookie "LSID[HttpOnly]" equals true
+cookie "LSID[Secure]" exists
+cookie "LSID[HttpOnly]" exists
 cookie "LSID[SameSite]" not exists
 
 
diff --git a/integration/tests/error_assert_query_cookie.err b/integration/tests/error_assert_query_cookie.err
new file mode 100644
index 000000000..712c78ea4
--- /dev/null
+++ b/integration/tests/error_assert_query_cookie.err
@@ -0,0 +1,16 @@
+error: Assert Failure
+  --> tests/error_assert_query_cookie.hurl:4:0
+   |
+ 4 | cookie "cookie1[Secure]" equals false  # This is not valid, Secure attribute exists or not but does have a value
+   |   actual:   none
+   |   expected: bool <false>
+   |
+
+error: Assert Failure
+  --> tests/error_assert_query_cookie.hurl:6:0
+   |
+ 6 | cookie "cookie2[Secure]" equals true   # This is not valid, Secure attribute exists or not but does have a value
+   |   actual:   unit
+   |   expected: bool <true>
+   |
+
diff --git a/integration/tests/error_assert_query_cookie.exit b/integration/tests/error_assert_query_cookie.exit
new file mode 100644
index 000000000..bf0d87ab1
--- /dev/null
+++ b/integration/tests/error_assert_query_cookie.exit
@@ -0,0 +1 @@
+4
\ No newline at end of file
diff --git a/integration/tests/error_assert_query_cookie.hurl b/integration/tests/error_assert_query_cookie.hurl
new file mode 100644
index 000000000..debaa443e
--- /dev/null
+++ b/integration/tests/error_assert_query_cookie.hurl
@@ -0,0 +1,8 @@
+GET http://localhost:8000/error-assert-query-cookie
+HTTP/1.0 200
+[Asserts]
+cookie "cookie1[Secure]" equals false  # This is not valid, Secure attribute exists or not but does have a value
+cookie "cookie1[Secure]" not exists
+cookie "cookie2[Secure]" equals true   # This is not valid, Secure attribute exists or not but does have a value
+cookie "cookie2[Secure]" exists
+
diff --git a/integration/tests/error_assert_query_cookie.py b/integration/tests/error_assert_query_cookie.py
new file mode 100644
index 000000000..54fe24c68
--- /dev/null
+++ b/integration/tests/error_assert_query_cookie.py
@@ -0,0 +1,10 @@
+from flask import request, make_response
+from tests import app
+
+@app.route("/error-assert-query-cookie")
+def error_assert_query_cookie():
+    resp = make_response()
+    resp.set_cookie('cookie1', 'value1')
+    resp.set_cookie('cookie2', 'value2', secure=True)
+    return resp
+
diff --git a/src/core/common.rs b/src/core/common.rs
index 3b60867df..d7081601a 100644
--- a/src/core/common.rs
+++ b/src/core/common.rs
@@ -34,6 +34,7 @@ pub enum DeprecatedValue {
 #[derive(Clone, Debug, PartialEq, Eq)]
 //#[derive(Clone, Debug, PartialEq, PartialOrd)]
 pub enum Value {
+    Unit,
     Bool(bool),
     Integer(i64),
 
@@ -65,6 +66,7 @@ impl fmt::Display for Value {
             Value::Nodeset(x) => format!("Nodeset{:?}", x),
             Value::Bytes(x) => format!("Bytes({:x?})", x),
             Value::Null => "Null".to_string(),
+            Value::Unit => "Unit".to_string(),
         };
         write!(f, "{}", value)
     }
@@ -81,7 +83,8 @@ impl Value {
             Value::Object(_) => "object".to_string(),
             Value::Nodeset(_) => "nodeset".to_string(),
             Value::Bytes(_) => "bytes".to_string(),
-            Value::Null => "unit".to_string(),
+            Value::Null => "null".to_string(),
+            Value::Unit => "unit".to_string(),
         }
     }
 
@@ -194,6 +197,7 @@ impl Serialize for Value {
                 serializer.serialize_str(&encoded)
             }
             Value::Null => serializer.serialize_none(),
+            Value::Unit => todo!("how to serialize that in json?"),
         }
     }
 }
@@ -213,6 +217,7 @@ impl Value {
             Value::Nodeset(_) => todo!(),
             Value::Bytes(_) => todo!(),
             Value::Null => todo!(),
+            Value::Unit => todo!(),
         }
     }
 
@@ -230,6 +235,7 @@ impl Value {
             Value::Nodeset(_) => todo!(),
             Value::Bytes(_) => todo!(),
             Value::Null => todo!(),
+            Value::Unit => todo!(),
         }
     }
 }
diff --git a/src/runner/predicate.rs b/src/runner/predicate.rs
index 2c072aafb..2b3400b00 100644
--- a/src/runner/predicate.rs
+++ b/src/runner/predicate.rs
@@ -126,6 +126,7 @@ impl Value {
             Value::Object(_) => "object".to_string(),
             Value::Bytes(values) => format!("byte array of size <{}>", values.len()),
             Value::Null => "null".to_string(),
+            Value::Unit => "unit".to_string(),
         }
     }
 }
@@ -396,7 +397,7 @@ impl PredicateFunc {
                             source_info: self.source_info.clone(),
                             inner: RunnerError::InvalidRegex(),
                             assert: false,
-                        })
+                        });
                     }
                 };
                 match value.clone() {
@@ -581,10 +582,7 @@ mod tests {
         );
         assert_eq!(error.source_info, SourceInfo::init(1, 0, 1, 0));
 
-        assert_eq!(
-            predicate.eval(&variables, Some(Value::Integer(1))).unwrap(),
-            ()
-        );
+        assert!(predicate.eval(&variables, Some(Value::Integer(1))).is_ok());
     }
 
     #[test]
@@ -609,6 +607,27 @@ mod tests {
         assert_eq!(assert_result.expected.as_str(), "int <10>");
     }
 
+    #[test]
+    fn test_predicate_type_mismatch_with_unit() {
+        let variables = HashMap::new();
+        let whitespace = Whitespace {
+            value: String::from(" "),
+            source_info: SourceInfo::init(0, 0, 0, 0),
+        };
+        let assert_result = PredicateFunc {
+            value: PredicateFuncValue::EqualInt {
+                space0: whitespace,
+                value: 10,
+            },
+            source_info: SourceInfo::init(0, 0, 0, 0),
+        }
+        .eval(&variables, Some(Value::Unit))
+        .unwrap();
+        assert_eq!(assert_result.success, false);
+        assert_eq!(assert_result.type_mismatch, true);
+        assert_eq!(assert_result.actual.as_str(), "unit");
+        assert_eq!(assert_result.expected.as_str(), "int <10>");
+    }
     #[test]
     fn test_predicate_value_error() {
         let variables = HashMap::new();
@@ -667,6 +686,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_predicate_exist() {
+        let variables = HashMap::new();
+        let predicate = PredicateFunc {
+            value: PredicateFuncValue::Exist {},
+            source_info: SourceInfo::init(0, 0, 0, 0),
+        };
+
+        let assert_result = predicate
+            .clone()
+            .eval(&variables, Some(Value::Unit))
+            .unwrap();
+        assert_eq!(assert_result.success, true);
+        assert_eq!(assert_result.actual.as_str(), "unit");
+        assert_eq!(assert_result.expected.as_str(), "something");
+
+        let assert_result = predicate.eval(&variables, None).unwrap();
+        assert_eq!(assert_result.success, false);
+        assert_eq!(assert_result.actual.as_str(), "none");
+        assert_eq!(assert_result.expected.as_str(), "something");
+    }
+
     #[test]
     fn test_predicate_value_equals() {
         let variables = HashMap::new();
diff --git a/src/runner/query.rs b/src/runner/query.rs
index 9186b2f06..cb93c274a 100644
--- a/src/runner/query.rs
+++ b/src/runner/query.rs
@@ -232,14 +232,14 @@ impl CookieAttributeName {
             CookieAttributeName::Path(_) => cookie.path().map(Value::String),
             CookieAttributeName::Secure(_) => {
                 if cookie.has_secure() {
-                    Some(Value::Bool(true))
+                    Some(Value::Unit)
                 } else {
                     None
                 }
             }
             CookieAttributeName::HttpOnly(_) => {
                 if cookie.has_httponly() {
-                    Some(Value::Bool(true))
+                    Some(Value::Unit)
                 } else {
                     None
                 }
@@ -616,7 +616,7 @@ pub mod tests {
         };
         assert_eq!(
             query.eval(&variables, response.clone()).unwrap().unwrap(),
-            Value::Bool(true)
+            Value::Unit
         );
 
         // cookie "LSID[Domain]"
@@ -698,13 +698,13 @@ pub mod tests {
             CookieAttributeName::Secure("_".to_string())
                 .eval(cookie.clone())
                 .unwrap(),
-            Value::Bool(true)
+            Value::Unit
         );
         assert_eq!(
             CookieAttributeName::HttpOnly("_".to_string())
                 .eval(cookie.clone())
                 .unwrap(),
-            Value::Bool(true)
+            Value::Unit
         );
         assert_eq!(
             CookieAttributeName::SameSite("_".to_string()).eval(cookie),