diff --git a/Cargo.lock b/Cargo.lock
index c3da4a33d6..e192474a47 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1344,6 +1344,7 @@ dependencies = [
 name = "leo-stdlib"
 version = "1.5.3"
 dependencies = [
+ "indexmap",
  "leo-ast",
  "leo-errors",
  "leo-span",
diff --git a/compiler/passes/src/type_checker/check_file.rs b/compiler/passes/src/type_checker/check_file.rs
index b8c61e38ff..3258fc28f7 100644
--- a/compiler/passes/src/type_checker/check_file.rs
+++ b/compiler/passes/src/type_checker/check_file.rs
@@ -26,6 +26,7 @@ impl<'a> ProgramVisitor<'a> for TypeChecker<'a> {
         self.parent = Some(input.name());
         input.input.iter().for_each(|i| {
             let input_var = i.get_variable();
+            self.validate_ident_type(&Some(input_var.type_));
 
             if let Err(err) = self.symbol_table.insert_variable(
                 input_var.identifier.name,
diff --git a/compiler/passes/src/type_checker/check_statements.rs b/compiler/passes/src/type_checker/check_statements.rs
index 4205462cc8..5c2e3204fc 100644
--- a/compiler/passes/src/type_checker/check_statements.rs
+++ b/compiler/passes/src/type_checker/check_statements.rs
@@ -29,10 +29,10 @@ impl<'a> StatementVisitorDirector<'a> for Director<'a> {
         // statements should always have some parent block
         let parent = self.visitor.parent.unwrap();
 
-        self.visit_expression(
-            &input.expression,
-            &self.visitor.symbol_table.lookup_fn(&parent).map(|f| f.output),
-        );
+        let return_type = &self.visitor.symbol_table.lookup_fn(&parent).map(|f| f.output);
+        self.visitor.validate_ident_type(return_type);
+
+        self.visit_expression(&input.expression, return_type);
     }
 
     fn visit_definition(&mut self, input: &'a DefinitionStatement) {
@@ -43,6 +43,8 @@ impl<'a> StatementVisitorDirector<'a> for Director<'a> {
         };
 
         input.variable_names.iter().for_each(|v| {
+            self.visitor.validate_ident_type(&Some(input.type_));
+
             if let Err(err) = self.visitor.symbol_table.insert_variable(
                 v.identifier.name,
                 VariableSymbol {
@@ -83,6 +85,7 @@ impl<'a> StatementVisitorDirector<'a> for Director<'a> {
         };
 
         if var_type.is_some() {
+            self.visitor.validate_ident_type(&var_type);
             self.visit_expression(&input.value, &var_type);
         }
     }
@@ -103,8 +106,10 @@ impl<'a> StatementVisitorDirector<'a> for Director<'a> {
             self.visitor.handler.emit_err(err);
         }
 
-        self.visit_expression(&input.start, &Some(input.type_));
-        self.visit_expression(&input.stop, &Some(input.type_));
+        let iter_type = &Some(input.type_);
+        self.visitor.validate_ident_type(iter_type);
+        self.visit_expression(&input.start, iter_type);
+        self.visit_expression(&input.stop, iter_type);
     }
 
     fn visit_console(&mut self, input: &'a ConsoleStatement) {
diff --git a/compiler/passes/src/type_checker/checker.rs b/compiler/passes/src/type_checker/checker.rs
index 5807fd7ee6..ce44547b2f 100644
--- a/compiler/passes/src/type_checker/checker.rs
+++ b/compiler/passes/src/type_checker/checker.rs
@@ -14,9 +14,11 @@
 // You should have received a copy of the GNU General Public License
 // along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
 
-use leo_ast::{IntegerType, Type};
+use indexmap::IndexSet;
+use leo_ast::{IntegerType, Node, Type};
 use leo_errors::{emitter::Handler, TypeCheckerError};
 use leo_span::{Span, Symbol};
+use leo_stdlib::*;
 
 use crate::SymbolTable;
 
@@ -25,6 +27,8 @@ pub struct TypeChecker<'a> {
     pub(crate) handler: &'a Handler,
     pub(crate) parent: Option<Symbol>,
     pub(crate) negate: bool,
+    pub(crate) account_types: IndexSet<Symbol>,
+    pub(crate) algorithms_types: IndexSet<Symbol>,
 }
 
 const INT_TYPES: [Type; 10] = [
@@ -74,6 +78,18 @@ impl<'a> TypeChecker<'a> {
             handler,
             parent: None,
             negate: false,
+            account_types: Account::types(),
+            algorithms_types: Algorithms::types(),
+        }
+    }
+
+    /// Validates that an ident type is a valid one.
+    pub(crate) fn validate_ident_type(&self, type_: &Option<Type>) {
+        if let Some(Type::Identifier(ident)) = type_ {
+            if !(self.account_types.contains(&ident.name) || self.algorithms_types.contains(&ident.name)) {
+                self.handler
+                    .emit_err(TypeCheckerError::invalid_built_in_type(&ident.name, ident.span()).into());
+            }
         }
     }
 
diff --git a/compiler/stdlib/Cargo.toml b/compiler/stdlib/Cargo.toml
index 90c1f9b756..2f75b2cf8e 100644
--- a/compiler/stdlib/Cargo.toml
+++ b/compiler/stdlib/Cargo.toml
@@ -28,7 +28,9 @@ version = "1.5.3"
 path = "../../leo/errors"
 version = "1.5.3"
 
-
 [dependencies.leo-span]
 path = "../../leo/span"
 version = "1.5.3"
+
+[dependencies]
+indexmap = "1.7.0"
\ No newline at end of file
diff --git a/compiler/stdlib/src/account/mod.rs b/compiler/stdlib/src/account/mod.rs
index 84c0fefc2b..d6b63ff9ad 100644
--- a/compiler/stdlib/src/account/mod.rs
+++ b/compiler/stdlib/src/account/mod.rs
@@ -16,34 +16,20 @@
 
 use crate::Types;
 
-use leo_ast::{Identifier, Type};
-use leo_span::{Span, Symbol};
+use indexmap::IndexSet;
+
+use leo_span::Symbol;
 
 pub struct Account;
 
 impl Types for Account {
-    fn types() -> Vec<Type> {
-        vec![
-            Type::Identifier(Identifier {
-                name: Symbol::intern("ComputeKey"),
-                span: Span::dummy(),
-            }),
-            Type::Identifier(Identifier {
-                name: Symbol::intern("PrivateKey"),
-                span: Span::dummy(),
-            }),
-            Type::Identifier(Identifier {
-                name: Symbol::intern("Record"),
-                span: Span::dummy(),
-            }),
-            Type::Identifier(Identifier {
-                name: Symbol::intern("Signature"),
-                span: Span::dummy(),
-            }),
-            Type::Identifier(Identifier {
-                name: Symbol::intern("ViewKey"),
-                span: Span::dummy(),
-            }),
-        ]
+    fn types() -> IndexSet<Symbol> {
+        IndexSet::from([
+            Symbol::intern("ComputeKey"),
+            Symbol::intern("PrivateKey"),
+            Symbol::intern("Record"),
+            Symbol::intern("Signature"),
+            Symbol::intern("ViewKey"),
+        ])
     }
 }
diff --git a/compiler/stdlib/src/algorithms/mod.rs b/compiler/stdlib/src/algorithms/mod.rs
index a8966275b2..2d77cb909f 100644
--- a/compiler/stdlib/src/algorithms/mod.rs
+++ b/compiler/stdlib/src/algorithms/mod.rs
@@ -16,16 +16,13 @@
 
 use crate::Types;
 
-use leo_ast::{Identifier, Type};
-use leo_span::{Span, Symbol};
+use indexmap::IndexSet;
+use leo_span::Symbol;
 
 pub struct Algorithms;
 
 impl Types for Algorithms {
-    fn types() -> Vec<Type> {
-        vec![Type::Identifier(Identifier {
-            name: Symbol::intern("Poseidon"),
-            span: Span::dummy(),
-        })]
+    fn types() -> IndexSet<Symbol> {
+        IndexSet::from([Symbol::intern("Poseidon")])
     }
 }
diff --git a/compiler/stdlib/src/lib.rs b/compiler/stdlib/src/lib.rs
index 4ecafecf86..6ebfa0d448 100644
--- a/compiler/stdlib/src/lib.rs
+++ b/compiler/stdlib/src/lib.rs
@@ -16,7 +16,8 @@
 
 #![doc = include_str!("../README.md")]
 
-use leo_ast::Type;
+use indexmap::IndexSet;
+use leo_span::Symbol;
 
 mod account;
 pub use account::*;
@@ -25,5 +26,5 @@ mod algorithms;
 pub use algorithms::*;
 
 pub trait Types {
-    fn types() -> Vec<Type>;
+    fn types() -> IndexSet<Symbol>;
 }
diff --git a/leo/errors/src/errors/type_checker/type_checker_error.rs b/leo/errors/src/errors/type_checker/type_checker_error.rs
index 6646d294ca..2965891cf4 100644
--- a/leo/errors/src/errors/type_checker/type_checker_error.rs
+++ b/leo/errors/src/errors/type_checker/type_checker_error.rs
@@ -132,4 +132,14 @@ create_messages!(
         ),
         help: None,
     }
+
+    /// For when an invalid built in type is used.
+    @formatted
+    invalid_built_in_type {
+        args: (type_: impl Display),
+        msg: format!(
+            "The type {type_} is not a valid built in type.",
+        ),
+        help: None,
+    }
 );