diff --git a/README.md b/README.md
index 5356a0e5..a55b041f 100755
--- a/README.md
+++ b/README.md
@@ -1165,7 +1165,7 @@ $ stat /bin/* | jc --stat -p
     "access_time": "2019-11-14 08:18:03.509681766 +0000",
     "modify_time": "2019-06-06 22:28:15.000000000 +0000",
     "change_time": "2019-08-12 17:21:29.521945390 +0000",
-    "birth_time": "-"
+    "birth_time": null
   },
   {
     "file": "/bin/btrfs",
@@ -1185,7 +1185,7 @@ $ stat /bin/* | jc --stat -p
     "access_time": "2019-11-14 08:18:28.990834276 +0000",
     "modify_time": "2018-03-12 23:04:27.000000000 +0000",
     "change_time": "2019-08-12 17:21:29.545944399 +0000",
-    "birth_time": "-"
+    "birth_time": null
   },
   ...
 ]
diff --git a/docs/parsers/stat.md b/docs/parsers/stat.md
index 86b8d226..f536f1ae 100644
--- a/docs/parsers/stat.md
+++ b/docs/parsers/stat.md
@@ -46,7 +46,7 @@ Examples:
         "access_time": "2019-11-14 08:18:28.990834276 +0000",
         "modify_time": "2018-03-12 23:04:27.000000000 +0000",
         "change_time": "2019-08-12 17:21:29.545944399 +0000",
-        "birth_time": "-"
+        "birth_time": null
       },
       ...
     ]
@@ -91,7 +91,7 @@ Examples:
         "access_time": "2019-11-14 08:18:28.990834276 +0000",
         "modify_time": "2018-03-12 23:04:27.000000000 +0000",
         "change_time": "2019-08-12 17:21:29.545944399 +0000",
-        "birth_time": "-"
+        "birth_time": null
       },
       ..
     ]
@@ -128,10 +128,10 @@ Returns:
         "user":         string,
         "gid":          integer,
         "group":        string,
-        "access_time":  string,
-        "modify_time":  string,
-        "change_time":  string,
-        "birth_time":   string
+        "access_time":  string,    # - = null
+        "modify_time":  string,    # - = null
+        "change_time":  string,    # - = null
+        "birth_time":   string     # - = null
       }
     ]
 
diff --git a/jc/parsers/stat.py b/jc/parsers/stat.py
index ee78475e..8417e0d7 100644
--- a/jc/parsers/stat.py
+++ b/jc/parsers/stat.py
@@ -45,7 +45,7 @@ Examples:
         "access_time": "2019-11-14 08:18:28.990834276 +0000",
         "modify_time": "2018-03-12 23:04:27.000000000 +0000",
         "change_time": "2019-08-12 17:21:29.545944399 +0000",
-        "birth_time": "-"
+        "birth_time": null
       },
       ...
     ]
@@ -90,7 +90,7 @@ Examples:
         "access_time": "2019-11-14 08:18:28.990834276 +0000",
         "modify_time": "2018-03-12 23:04:27.000000000 +0000",
         "change_time": "2019-08-12 17:21:29.545944399 +0000",
-        "birth_time": "-"
+        "birth_time": null
       },
       ..
     ]
@@ -127,10 +127,10 @@ def process(proc_data):
             "user":         string,
             "gid":          integer,
             "group":        string,
-            "access_time":  string,
-            "modify_time":  string,
-            "change_time":  string,
-            "birth_time":   string
+            "access_time":  string,    # - = null
+            "modify_time":  string,    # - = null
+            "change_time":  string,    # - = null
+            "birth_time":   string     # - = null
           }
         ]
     """
@@ -144,6 +144,14 @@ def process(proc_data):
                 except (ValueError):
                     entry[key] = None
 
+    # turn - into null for time fields
+    for entry in proc_data:
+        null_list = ['access_time', 'modify_time', 'change_time', 'birth_time']
+        for key in null_list:
+            if key in entry:
+                if entry[key] == '-':
+                    entry[key] = None
+
     return proc_data