diff --git a/mypy/pyinfo.py b/mypy/pyinfo.py
index 3834c04e218e9..ab2d3286bd5cf 100644
--- a/mypy/pyinfo.py
+++ b/mypy/pyinfo.py
@@ -19,7 +19,7 @@
 
 def getprefixes():
     # type: () -> Tuple[str, str]
-    return sys.base_prefix, sys.prefix
+    return getattr(sys, "base_prefix", sys.prefix), sys.prefix
 
 
 def getsitepackages():