diff --git a/artiq/compiler/fold_constants.py b/artiq/compiler/fold_constants.py
index 191a1e95e..0e0507df5 100644
--- a/artiq/compiler/fold_constants.py
+++ b/artiq/compiler/fold_constants.py
@@ -1,6 +1,7 @@
 import ast, operator
 
 from artiq.compiler.tools import *
+from artiq.language.core import int64, round64
 
 _ast_unops = {
 	ast.Invert: operator.inv,
@@ -57,5 +58,18 @@ class _ConstantFolder(ast.NodeTransformer):
 			return node
 		return ast.copy_location(result, node)
 
+	def visit_Call(self, node):
+		self.generic_visit(node)
+		fn = node.func.id
+		if fn in ("int", "int64", "round", "round64"):
+			try:
+				arg = eval_constant(node.args[0])
+			except NotConstant:
+				return node
+			result = value_to_ast(globals()[fn](arg))
+			return ast.copy_location(result, node)
+		else:
+			return node
+
 def fold_constants(node):
 	_ConstantFolder().visit(node)