diff --git a/httpie/context.py b/httpie/context.py
index ad17a1ca..945b3c15 100644
--- a/httpie/context.py
+++ b/httpie/context.py
@@ -112,18 +112,16 @@ class Environment:
                     self.log_error(e, level='warning')
         return config
 
-    
-    @property 
+    @property
     def devnull(self) -> IO:
         if self._devnull is None:
             self._devnull = open(os.devnull, 'w+')
         return self._devnull
 
-    #For ease of testing
     @devnull.setter
     def devnull(self, value):
         self._devnull = value
-        
+
     def log_error(self, msg, level='error'):
         assert level in ['error', 'warning']
         self.stderr.write(f'\n{self.program_name}: {level}: {msg}\n\n')
diff --git a/tests/test_downloads.py b/tests/test_downloads.py
index 48180180..21623b56 100644
--- a/tests/test_downloads.py
+++ b/tests/test_downloads.py
@@ -199,4 +199,3 @@ class TestDownloads:
         assert r.stderr == ''
         assert env.devnull == env.stderr
         assert env.devnull == env.stdout
-
diff --git a/tests/test_output.py b/tests/test_output.py
index 4de77196..41ef5d3f 100644
--- a/tests/test_output.py
+++ b/tests/test_output.py
@@ -2,7 +2,7 @@ import argparse
 import mock
 import json
 import os
-import io 
+import io
 from tempfile import gettempdir
 from urllib.request import urlopen
 
@@ -54,18 +54,18 @@ class TestQuietFlag:
         assert env.stdout == env.devnull
         assert env.stderr == env.devnull
         assert r.stderr == ''
-        assert HTTP_OK in r.devnull.decode()
+        assert HTTP_OK in r.devnull
         assert str(r) == ''
 
     @mock.patch('httpie.cli.argtypes.AuthCredentials._getpass',
-                new=lambda self, prompt:'password')
+                new=lambda self, prompt: 'password')
     def test_quiet_password_prompt(self, httpbin):
         """ Tests whether httpie still prompts for password when request
         requires authetication and only username is provided"""
         env = MockEnvironment(stdin_isatty=True, stdout_isatty=True)
         env.devnull = io.BytesIO()
-        r = http('--quiet', '--auth', 'user','GET', httpbin.url + '/basic-auth/user/password', env=env)
-        assert HTTP_OK in r.devnull.decode()
+        r = http('--quiet', '--auth', 'user', 'GET', httpbin.url + '/basic-auth/user/password', env=env)
+        assert HTTP_OK in r.devnull
         assert env.stdout == env.devnull
         assert env.stderr == env.devnull
         assert str(r) == ''
@@ -80,6 +80,7 @@ class TestQuietFlag:
         assert str(r) == ''
         assert r.stderr == ''
 
+
 class TestVerboseFlag:
     def test_verbose(self, httpbin):
         r = http('--verbose',
diff --git a/tests/utils.py b/tests/utils.py
index b73d1117..829e9f27 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -94,12 +94,12 @@ class BaseCLIResponse:
 
         - stdout output: print(self)
         - stderr output: print(self.stderr)
-        - devnull output: print(self.devnull) 
+        - devnull output: print(self.devnull)
         - exit_status output: print(self.exit_status)
 
     """
     stderr: str = None
-    devnull: str = None 
+    devnull: str = None
     json: dict = None
     exit_status: ExitStatus = None
 
@@ -163,20 +163,21 @@ def http(
     # noinspection PyUnresolvedReferences
     """
     Run HTTPie and capture stderr/out and exit status.
-    Content writtent to devnull will be captured if 
-    env.devnull in env does not correspond to os.devnull file. 
+    Content writtent to devnull will be captured only if
+    env.devnull is set manually.
 
     Invoke `httpie.core.main()` with `args` and `kwargs`,
     and return a `CLIResponse` subclass instance.
 
     The return value is either a `StrCLIResponse`, or `BytesCLIResponse`
-    if unable to decode the output. 
+    if unable to decode the output. Devnull is string when possible,
+    bytes otherwise.
 
     The response has the following attributes:
 
         `stdout` is represented by the instance itself (print r)
         `stderr`: text written to stderr
-        `devnull` text written to devnull. String if possible bytes otherwise
+        `devnull` text written to devnull.
         `exit_status`: the exit status
         `json`: decoded JSON (if possible) or `None`
 
@@ -264,7 +265,11 @@ def http(
             r = BytesCLIResponse(output)
         else:
             r = StrCLIResponse(output)
-            
+
+        try:
+            devnull_output = devnull_output.decode('utf8')
+        except Exception:
+            pass
 
         r.devnull = devnull_output
         r.stderr = stderr.read()