diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
index f2e9d5bd3..a2f1971dc 100644
--- a/artiq/compiler/transforms/artiq_ir_generator.py
+++ b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -1813,7 +1813,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
             assert None not in args
 
         if self.unwind_target is None or \
-                types.is_function(callee.type) and "nounwind" in callee.type.flags:
+                types.is_c_function(callee.type) and "nounwind" in callee.type.flags:
             insn = self.append(ir.Call(func, args, arg_exprs))
         else:
             after_invoke = self.add_block("invoke")