diff --git a/src/execnet/gateway_base.py b/src/execnet/gateway_base.py
index 9ba25b42..252bdbcb 100644
--- a/src/execnet/gateway_base.py
+++ b/src/execnet/gateway_base.py
@@ -207,6 +207,9 @@ def get_ident(self) -> int:
 
     def sleep(self, delay: float) -> None:
         import eventlet
+# f = open("/tmp/execnet-%s" % os.getpid(), "w")
+# def log_extra(*msg):
+#     f.write(" ".join([str(x) for x in msg]) + "\n")
 
         eventlet.sleep(delay)
 
diff --git a/src/execnet/gateway_bootstrap.py b/src/execnet/gateway_bootstrap.py
index e9d7efe1..d2cd5f1d 100644
--- a/src/execnet/gateway_bootstrap.py
+++ b/src/execnet/gateway_bootstrap.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import inspect
+import json
 import os
 
 import execnet
@@ -25,13 +26,13 @@ def bootstrap_import(io: IO, spec: XSpec) -> None:
     sendexec(
         io,
         "import sys",
-        "if %r not in sys.path:" % importdir,
-        "    sys.path.insert(0, %r)" % importdir,
+        f"if {importdir!r} not in sys.path:",
+        f"    sys.path.insert(0, {importdir!r})",
         "from execnet.gateway_base import serve, init_popen_io, get_execmodel",
         "sys.stdout.write('1')",
         "sys.stdout.flush()",
-        "execmodel = get_execmodel(%r)" % spec.execmodel,
-        "serve(init_popen_io(execmodel), id='%s-worker')" % spec.id,
+        f"execmodel = get_execmodel({spec.execmodel!r})",
+        f"serve(init_popen_io(execmodel), id='{spec.id}-worker')",
     )
     s = io.read(1)
     assert s == b"1", repr(s)
@@ -77,7 +78,8 @@ def bootstrap_socket(io: IO, id) -> None:
 
 def sendexec(io: IO, *sources: str) -> None:
     source = "\n".join(sources)
-    io.write((repr(source) + "\n").encode("utf-8"))
+    encoded = (json.dumps(source) + "\n").encode("utf-8")
+    io.write(encoded)
 
 
 def bootstrap(io: IO, spec: XSpec) -> execnet.Gateway:
diff --git a/src/execnet/gateway_io.py b/src/execnet/gateway_io.py
index 21285ab4..27cc8ddc 100644
--- a/src/execnet/gateway_io.py
+++ b/src/execnet/gateway_io.py
@@ -48,7 +48,7 @@ def kill(self) -> None:
             sys.stderr.flush()
 
 
-popen_bootstrapline = "import sys;exec(eval(sys.stdin.readline()))"
+popen_bootstrapline = "import sys;import json;exec(json.loads(sys.stdin.readline()))"
 
 
 def shell_split_path(path: str) -> list[str]:
diff --git a/testing/test_basics.py b/testing/test_basics.py
index 76d2aab7..11adeacd 100644
--- a/testing/test_basics.py
+++ b/testing/test_basics.py
@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import inspect
+import json
 import os
 import subprocess
 import sys
@@ -93,7 +94,9 @@ def receive() -> str:
 
     try:
         source = inspect.getsource(read_write_loop) + "read_write_loop()"
-        send(repr(source) + "\n")
+        repr_source = json.dumps(source) + "\n"
+        sendline = repr_source
+        send(sendline)
         s = receive()
         assert s == "ok\n"
         send("hello\n")