diff --git a/src/agent/mod.rs b/src/agent/mod.rs
index 9dcd1402..235b7c1f 100644
--- a/src/agent/mod.rs
+++ b/src/agent/mod.rs
@@ -5608,20 +5608,26 @@ pub(crate) fn global_declaration_instantiation(
     let lex_names = script.lexically_declared_names();
     let var_names = script.var_declared_names();
     for name in lex_names {
-        if env.has_var_declaration(&name) {
-            return Err(create_syntax_error(format!("{name}: already defined"), None));
-        }
         if env.has_lexical_declaration(&name) {
-            return Err(create_syntax_error(format!("{name}: already defined"), None));
+            return Err(create_syntax_error(
+                format!("lexical {name}: already defined in existing lexical declarations"),
+                None,
+            ));
         }
         let has_restricted_global = env.has_restricted_global_property(&name)?;
         if has_restricted_global {
-            return Err(create_syntax_error(format!("{name} is restricted and may not be used"), None));
+            return Err(create_syntax_error(
+                format!("{name} is a restricted global property and may not be used as a lexical declaration"),
+                None,
+            ));
         }
     }
     for name in var_names {
         if env.has_lexical_declaration(&name) {
-            return Err(create_syntax_error(format!("{name}: already defined"), None));
+            return Err(create_syntax_error(
+                format!("var {name}: already defined in existing lexical declarations"),
+                None,
+            ));
         }
     }
     let var_declarations = script.var_scoped_declarations();
diff --git a/src/agent/tests.rs b/src/agent/tests.rs
index 8baaaef5..6c5e1ff3 100644
--- a/src/agent/tests.rs
+++ b/src/agent/tests.rs
@@ -1168,10 +1168,10 @@ mod global_declaration_instantiation {
     use test_case::test_case;
 
     #[test_case("var a" => Ok((sset(&["a"]), sset(&[]))); "one simple var-declared variable")]
-    #[test_case("let already_var_declared;" => serr("SyntaxError: already_var_declared: already defined"); "existing var decl")]
-    #[test_case("let existing_mutable;" => serr("SyntaxError: existing_mutable: already defined"); "existing lex decl")]
-    #[test_case("let undefined;" => serr("SyntaxError: undefined is restricted and may not be used"); "restricted global")]
-    #[test_case("var existing_mutable;" => serr("SyntaxError: existing_mutable: already defined"); "var dups lex")]
+    #[test_case("let already_var_declared;" => serr("SyntaxError: already_var_declared is a restricted global property and may not be used as a lexical declaration"); "existing var decl")]
+    #[test_case("let existing_mutable;" => serr("SyntaxError: lexical existing_mutable: already defined in existing lexical declarations"); "existing lex decl")]
+    #[test_case("let undefined;" => serr("SyntaxError: undefined is a restricted global property and may not be used as a lexical declaration"); "restricted global")]
+    #[test_case("var existing_mutable;" => serr("SyntaxError: var existing_mutable: already defined in existing lexical declarations"); "var dups lex")]
     #[test_case("function undefined(){}" => serr("TypeError: Cannot create global function undefined"); "function named undefined")]
     #[test_case("var a; let b; const c=0; for (var item in object) {}" => Ok((sset(&["a", "item"]), sset(&["b", "c"]))); "many")]
     #[test_case("class bob{}" => Ok((sset(&[]), sset(&["bob"]))); "a class")]
diff --git a/src/environment_record/mod.rs b/src/environment_record/mod.rs
index 3d22caaf..c0d7fe39 100644
--- a/src/environment_record/mod.rs
+++ b/src/environment_record/mod.rs
@@ -1360,19 +1360,6 @@ impl EnvironmentRecord for GlobalEnvironmentRecord {
 }
 
 impl GlobalEnvironmentRecord {
-    // HasVarDeclaration ( N )
-    //
-    // The HasVarDeclaration concrete method of a global Environment Record envRec takes argument N (a String). It
-    // determines if the argument identifier has a binding in this record that was created using a VariableStatement or
-    // a FunctionDeclaration. It performs the following steps when called:
-    //
-    //  1. Let varDeclaredNames be envRec.[[VarNames]].
-    //  2. If varDeclaredNames contains N, return true.
-    //  3. Return false.
-    pub(crate) fn has_var_declaration(&self, name: &JSString) -> bool {
-        self.var_names.borrow().contains(name)
-    }
-
     // HasLexicalDeclaration ( N )
     //
     // The HasLexicalDeclaration concrete method of a global Environment Record envRec takes argument N (a String). It
diff --git a/src/environment_record/tests.rs b/src/environment_record/tests.rs
index 149d1bd3..2bd4a714 100644
--- a/src/environment_record/tests.rs
+++ b/src/environment_record/tests.rs
@@ -1810,24 +1810,6 @@ mod global_environment_record {
         assert_eq!(result, ECMAScriptValue::from(this_object));
     }
 
-    #[test_case("varstyle" => true; "var")]
-    #[test_case("lexical" => false; "lex")]
-    fn has_var_declaration(prop_name: &str) -> bool {
-        // Setup
-        setup_test_agent();
-        let object_prototype = intrinsic(IntrinsicId::ObjectPrototype);
-        let global_object = ordinary_object_create(Some(object_prototype.clone()));
-        let this_object = ordinary_object_create(Some(object_prototype));
-        let ger = GlobalEnvironmentRecord::new(global_object, this_object, "test");
-        let var_name = JSString::from("varstyle");
-        ger.create_global_var_binding(var_name, true).unwrap();
-        let lex_name = JSString::from("lexical");
-        ger.create_mutable_binding(lex_name.clone(), true).unwrap();
-        ger.initialize_binding(&lex_name, ECMAScriptValue::Undefined).unwrap();
-
-        // Exercise
-        ger.has_var_declaration(&JSString::from(prop_name))
-    }
     #[test_case("varstyle" => false; "var")]
     #[test_case("lexical" => true; "lex")]
     fn has_lexical_declaration(prop_name: &str) -> bool {