diff --git a/execnet/gateway_bootstrap.py b/execnet/gateway_bootstrap.py
index 30b6d866..ba5bf104 100644
--- a/execnet/gateway_bootstrap.py
+++ b/execnet/gateway_bootstrap.py
@@ -75,7 +75,7 @@ def bootstrap_socket(io, id):
 
 def sendexec(io, *sources):
     source = "\n".join(sources)
-    io.write((repr(source) + "\n").encode("ascii"))
+    io.write((repr(source) + "\n").encode("utf-8"))
 
 
 def fix_pid_for_jython_popen(gw):