diff --git a/src/pip/_internal/utils/outdated.py b/src/pip/_internal/utils/outdated.py
index e1f9129d1..2525a7955 100644
--- a/src/pip/_internal/utils/outdated.py
+++ b/src/pip/_internal/utils/outdated.py
@@ -78,15 +78,13 @@ class SelfCheckState(object):
 
         # Attempt to write out our version check file
         with lockfile.LockFile(self.statefile_path):
-            if os.path.exists(self.statefile_path):
-                with open(self.statefile_path) as statefile:
-                    state = json.load(statefile)
-            else:
-                state = {}
-
-            state[self.key] = {
-                "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
-                "pypi_version": pypi_version,
+            # Since we have a prefix-specific state file, we can just
+            # overwrite whatever is there, no need to check.
+            state = {
+                self.key: {
+                    "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
+                    "pypi_version": pypi_version,
+                },
             }
 
             with open(self.statefile_path, "w") as statefile:
diff --git a/tests/unit/test_unit_outdated.py b/tests/unit/test_unit_outdated.py
index 6a7c6a0e0..04c641408 100644
--- a/tests/unit/test_unit_outdated.py
+++ b/tests/unit/test_unit_outdated.py
@@ -197,7 +197,6 @@ def test_self_check_state(monkeypatch, tmpdir):
     assert fake_lock.calls == [pretend.call(expected_path)]
 
     assert fake_open.calls == [
-        pretend.call(expected_path),
         pretend.call(expected_path),
         pretend.call(expected_path, 'w'),
     ]