diff --git a/jedi/_compatibility.py b/jedi/_compatibility.py
index 573b90bd..cec07a4c 100644
--- a/jedi/_compatibility.py
+++ b/jedi/_compatibility.py
@@ -507,5 +507,10 @@ class GeneralizedPopen(subprocess.Popen):
     def __init__(self, *args, **kwargs):
         creation_flags = 0
         if os.name == 'nt':
-            creation_flags = subprocess.CREATE_NO_WINDOW
+            try:
+                # Was introduced in Python 3.7.
+                CREATE_NO_WINDOW = subprocess.CREATE_NO_WINDOW
+            except AttributeError:
+                CREATE_NO_WINDOW = 0x08000000
+            creation_flags = CREATE_NO_WINDOW
         super(GeneralizedPopen, self).__init__(*args, creationflags=creation_flags, **kwargs)