diff --git a/gunicorn/pidfile.py b/gunicorn/pidfile.py
index 4cf603c7..45b32de1 100644
--- a/gunicorn/pidfile.py
+++ b/gunicorn/pidfile.py
@@ -66,7 +66,10 @@ class Pidfile(object):
             return
         try:
             with open(self.fname, "r") as f:
-                wpid = int(f.read() or 0)
+                try:
+                    wpid = int(f.read())
+                except ValueError:
+                    wpid = 0
 
                 if wpid <= 0:
                     return