diff --git a/AUTHORS b/AUTHORS
index 6288f8c1b02..aa2237c6837 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -256,6 +256,7 @@ Tim Hoffmann
 Tim Strazny
 Tom Dalton
 Tom Viner
+Tomáš Gavenčiak
 Tomer Keren
 Trevor Bekolay
 Tyler Goodlet
diff --git a/changelog/6557.bugfix.rst b/changelog/6557.bugfix.rst
new file mode 100644
index 00000000000..fb7527d9960
--- /dev/null
+++ b/changelog/6557.bugfix.rst
@@ -0,0 +1 @@
+Make capture output streams ``.write()`` method return the same return value from original streams.
diff --git a/src/_pytest/capture.py b/src/_pytest/capture.py
index 0cd3ce60427..c79bfeef024 100644
--- a/src/_pytest/capture.py
+++ b/src/_pytest/capture.py
@@ -424,7 +424,7 @@ def write(self, obj):
             raise TypeError(
                 "write() argument must be str, not {}".format(type(obj).__name__)
             )
-        self.buffer.write(obj)
+        return self.buffer.write(obj)
 
     def writelines(self, linelist):
         data = "".join(linelist)
diff --git a/testing/test_capture.py b/testing/test_capture.py
index 27f8d7d56e7..7d459e91c75 100644
--- a/testing/test_capture.py
+++ b/testing/test_capture.py
@@ -1492,3 +1492,8 @@ def test_fails():
     result_with_capture.stdout.fnmatch_lines(
         ["E * TypeError: write() argument must be str, not bytes"]
     )
+
+
+def test_stderr_write_returns_len(capsys):
+    """Write on Encoded files, namely captured stderr, should return number of characters written."""
+    assert sys.stderr.write("Foo") == 3