diff --git a/Lib/os.py b/Lib/os.py
index abbadc4..40d117e 100644
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -514,11 +514,7 @@
 __all__.append("getenv")
 
 def _exists(name):
-    try:
-        eval(name)
-        return True
-    except NameError:
-        return False
+    return name in globals()
 
 # Supply spawn*() (probably only for Unix)
 if _exists("fork") and not _exists("spawnv") and _exists("execv"):