diff --git a/src/python/pants/backend/python/tasks/select_interpreter.py b/src/python/pants/backend/python/tasks/select_interpreter.py
index e7e11b526587..01fdf5354394 100644
--- a/src/python/pants/backend/python/tasks/select_interpreter.py
+++ b/src/python/pants/backend/python/tasks/select_interpreter.py
@@ -94,8 +94,8 @@ def _get_interpreter(interpreter_path_file):
     with open(interpreter_path_file, 'r') as infile:
       lines = infile.readlines()
       binary = lines[0].strip()
-      extras = {}
+      interpreter = PythonInterpreter.from_binary(binary)
       for line in lines[1:]:
         dist_name, dist_version, location = line.strip().split('\t')
-        extras[(dist_name, dist_version)] = location
-    return PythonInterpreter.from_binary(binary, extras.values())
+        interpreter = interpreter.with_extra(dist_name, dist_version, location)
+      return interpreter