diff --git a/lang/ast/const.c b/lang/ast/const.c
new file mode 100644
index 0000000..2215e91
--- /dev/null
+++ b/lang/ast/const.c
@@ -0,0 +1,19 @@
+#include "ctx.h"
+#include "node.h"
+
+#include <blue/object/string.h>
+
+struct ast_node_type c_true_node_ops = {
+	.n_state_size = sizeof(struct parser_state),
+	.n_node_size = sizeof(struct ivy_ast_node),
+};
+
+struct ast_node_type c_false_node_ops = {
+	.n_state_size = sizeof(struct parser_state),
+	.n_node_size = sizeof(struct ivy_ast_node),
+};
+
+struct ast_node_type c_null_node_ops = {
+	.n_state_size = sizeof(struct parser_state),
+	.n_node_size = sizeof(struct ivy_ast_node),
+};
diff --git a/lang/ast/expr/arith.c b/lang/ast/expr/arith.c
index 8511de8..3a88436 100644
--- a/lang/ast/expr/arith.c
+++ b/lang/ast/expr/arith.c
@@ -119,6 +119,15 @@ enum ivy_status arith_push_operand(
 		case IVY_KW_CONTINUE:
 			v = ast_node_create(IVY_AST_LOOP_REPEAT);
 			break;
+		case IVY_KW_TRUE:
+			v = ast_node_create(IVY_AST_C_TRUE);
+			break;
+		case IVY_KW_FALSE:
+			v = ast_node_create(IVY_AST_C_FALSE);
+			break;
+		case IVY_KW_NULL:
+			v = ast_node_create(IVY_AST_C_NULL);
+			break;
 		default:
 			return IVY_ERR_BAD_SYNTAX;
 		}
diff --git a/lang/ast/expr/expr.c b/lang/ast/expr/expr.c
index 7730258..82ccfee 100644
--- a/lang/ast/expr/expr.c
+++ b/lang/ast/expr/expr.c
@@ -91,6 +91,11 @@ struct ast_node_type expr_node_ops = {
 		KW_PARSER(FINALLY, stmt_parse_end),
 		KW_PARSER(END, stmt_parse_end),
 
+		/* keyword constants */
+		KW_PARSER(TRUE, arith_parse_operand),
+		KW_PARSER(FALSE, arith_parse_operand),
+		KW_PARSER(NULL, arith_parse_operand),
+
 		/* operator/block keywords */
 		KW_PARSER(IN, arith_parse_in),
 		KW_PARSER(IS, arith_parse_operator),
diff --git a/lang/ast/expr/expr.h b/lang/ast/expr/expr.h
index d62162c..99160d2 100644
--- a/lang/ast/expr/expr.h
+++ b/lang/ast/expr/expr.h
@@ -44,6 +44,7 @@ enum expr_component {
 	EXPR_CMP_OPERATOR,
 	EXPR_CMP_OPERAND,
 	EXPR_CMP_MSG,
+	EXPR_CMP_KEYWORD,
 };
 
 struct expr_parser_state {
diff --git a/lang/ast/node.c b/lang/ast/node.c
index b07aedb..e451693 100644
--- a/lang/ast/node.c
+++ b/lang/ast/node.c
@@ -42,6 +42,9 @@ extern struct ast_node_type pkg_dynamic_node_ops;
 extern struct ast_node_type discard_node_ops;
 extern struct ast_node_type try_node_ops;
 extern struct ast_node_type try_catch_node_ops;
+extern struct ast_node_type c_true_node_ops;
+extern struct ast_node_type c_false_node_ops;
+extern struct ast_node_type c_null_node_ops;
 
 static const struct ast_node_type *node_ops[] = {
 	[IVY_AST_UNIT] = &unit_node_ops,
@@ -80,6 +83,9 @@ static const struct ast_node_type *node_ops[] = {
 	[IVY_AST_DISCARD] = &discard_node_ops,
 	[IVY_AST_TRY] = &try_node_ops,
 	[IVY_AST_TRY_CATCH] = &try_catch_node_ops,
+	[IVY_AST_C_TRUE] = &c_true_node_ops,
+	[IVY_AST_C_FALSE] = &c_false_node_ops,
+	[IVY_AST_C_NULL] = &c_null_node_ops,
 };
 static const size_t nr_node_ops = sizeof node_ops / sizeof node_ops[0];
 
@@ -129,6 +135,9 @@ enum token_expr_type get_token_expr_type(struct ivy_token *tok)
 		case IVY_KW_CONTINUE:
 		case IVY_KW_TRY:
 		case IVY_KW_THROW:
+		case IVY_KW_TRUE:
+		case IVY_KW_FALSE:
+		case IVY_KW_NULL:
 			return TOK_EXPR_BEGIN;
 		default:
 			op = ivy_operator_get_by_token(tok->t_keyword);
@@ -379,6 +388,9 @@ const char *ivy_ast_node_type_to_string(enum ivy_ast_node_type v)
 		ENUM_STR(IVY_AST_TRY);
 		ENUM_STR(IVY_AST_TRY_CATCH);
 		ENUM_STR(IVY_AST_TYPE_COUNT);
+		ENUM_STR(IVY_AST_C_TRUE);
+		ENUM_STR(IVY_AST_C_FALSE);
+		ENUM_STR(IVY_AST_C_NULL);
 	default:
 		return "";
 	}