diff --git a/gpio/__init__.py b/gpio/__init__.py
index c6f37f7..10cf9d3 100644
--- a/gpio/__init__.py
+++ b/gpio/__init__.py
@@ -2,6 +2,7 @@
 __version__ = '1.0.0'
 
 from threading import Lock
+from time import sleep, time
 try:
     from collections.abc import Iterable
 except ImportError:
@@ -16,7 +17,9 @@
 GPIO_ROOT = '/sys/class/gpio'
 GPIO_EXPORT = os.path.join(GPIO_ROOT, 'export')
 GPIO_UNEXPORT = os.path.join(GPIO_ROOT, 'unexport')
-FMODE = 'w+'  # w+ overwrites and truncates existing files
+FMODE_STR_WO = 'w'   # /sys/class/gpio/export is not readable, even by root
+FMODE_STR_RW = 'w+'  # w+ overwrites and truncates existing files
+FMODE_BIN_RW = 'wb+' # Using unbuffered binary IO is ~ 3x faster than text
 IN, OUT = 'in', 'out'
 LOW, HIGH = 0, 1
 
@@ -46,12 +49,18 @@ def __init__(self, pin, direction=None, initial=LOW, active_low=None):
 
         if not os.path.exists(self.root):
             with _export_lock:
-                with open(GPIO_EXPORT, FMODE) as f:
+                with open(GPIO_EXPORT, FMODE_STR_WO) as f:
                     f.write(str(self.pin))
                     f.flush()
+            gpio_gid = os.stat(GPIO_ROOT).st_gid
+            value_path = os.path.join(self.root, 'value')
+            start = time()
+            # give udev a moment to update the group of newly created files
+            while os.stat(value_path).st_gid != gpio_gid and time() - start < .5:
+                sleep(.01)
 
         # Using unbuffered binary IO is ~ 3x faster than text
-        self.value = open(os.path.join(self.root, 'value'), 'wb+', buffering=0)
+        self.value = open(os.path.join(self.root, 'value'), FMODE_BIN_RW, buffering=0)
 
         # I hate manually calling .setup()!
         self.setup(direction, initial, active_low)
@@ -100,7 +109,7 @@ def get_direction(self):
         Returns:
             str: "in" or "out"
         '''
-        with open(os.path.join(self.root, 'direction'), FMODE) as f:
+        with open(os.path.join(self.root, 'direction'), FMODE_STR_RW) as f:
             return f.read().strip()
 
     def set_direction(self, mode):
@@ -112,7 +121,7 @@ def set_direction(self, mode):
         if mode not in (IN, OUT, LOW, HIGH):
             raise ValueError("Unsupported pin mode {}".format(mode))
 
-        with open(os.path.join(self.root, 'direction'), FMODE) as f:
+        with open(os.path.join(self.root, 'direction'), FMODE_STR_RW) as f:
             f.write(str(mode))
             f.flush()
 
@@ -125,7 +134,7 @@ def set_active_low(self, active_low):
         if not isinstance(active_low, bool):
             raise ValueError("active_low must be True or False")
 
-        with open(os.path.join(self.root, 'active_low'), FMODE) as f:
+        with open(os.path.join(self.root, 'active_low'), FMODE_STR_RW) as f:
             f.write('1' if active_low else '0')
             f.flush()
 
@@ -168,7 +177,7 @@ def cleanup(self):
 
         if os.path.exists(self.root):
             with _export_lock:
-                with open(GPIO_UNEXPORT, FMODE) as f:
+                with open(GPIO_UNEXPORT, FMODE_STR_WO) as f:
                     f.write(str(self.pin))
                     f.flush()