diff --git a/changelog/3775.bugfix.rst b/changelog/3775.bugfix.rst
new file mode 100644
index 000000000..dd5263f74
--- /dev/null
+++ b/changelog/3775.bugfix.rst
@@ -0,0 +1 @@
+Fix bug where importing modules or other objects with prefix ``pytest_`` prefix would raise a ``PluginValidationError``.
diff --git a/src/_pytest/config/__init__.py b/src/_pytest/config/__init__.py
index 421d124e9..921b3ef20 100644
--- a/src/_pytest/config/__init__.py
+++ b/src/_pytest/config/__init__.py
@@ -1,6 +1,7 @@
 """ command line options, ini-file and conftest.py processing. """
 from __future__ import absolute_import, division, print_function
 import argparse
+import inspect
 import shlex
 import traceback
 import types
@@ -252,6 +253,10 @@ class PytestPluginManager(PluginManager):
         method = getattr(plugin, name)
         opts = super(PytestPluginManager, self).parse_hookimpl_opts(plugin, name)
 
+        # consider only actual functions for hooks (#3775)
+        if not inspect.isroutine(method):
+            return
+
         # collect unmarked hooks as long as they have the `pytest_' prefix
         if opts is None and name.startswith("pytest_"):
             opts = {}
diff --git a/testing/example_scripts/config/collect_pytest_prefix/conftest.py b/testing/example_scripts/config/collect_pytest_prefix/conftest.py
new file mode 100644
index 000000000..56a4c71d3
--- /dev/null
+++ b/testing/example_scripts/config/collect_pytest_prefix/conftest.py
@@ -0,0 +1,2 @@
+class pytest_something(object):
+    pass
diff --git a/testing/example_scripts/config/collect_pytest_prefix/test_foo.py b/testing/example_scripts/config/collect_pytest_prefix/test_foo.py
new file mode 100644
index 000000000..8f2d73cfa
--- /dev/null
+++ b/testing/example_scripts/config/collect_pytest_prefix/test_foo.py
@@ -0,0 +1,2 @@
+def test_foo():
+    pass
diff --git a/testing/test_config.py b/testing/test_config.py
index b507bb8e8..ef9dacd9c 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -745,6 +745,24 @@ def test_get_plugin_specs_as_list():
     assert _get_plugin_specs_as_list(("foo", "bar")) == ["foo", "bar"]
 
 
+def test_collect_pytest_prefix_bug_integration(testdir):
+    """Integration test for issue #3775"""
+    p = testdir.copy_example("config/collect_pytest_prefix")
+    result = testdir.runpytest(p)
+    result.stdout.fnmatch_lines("* 1 passed *")
+
+
+def test_collect_pytest_prefix_bug(pytestconfig):
+    """Ensure we collect only actual functions from conftest files (#3775)"""
+
+    class Dummy(object):
+        class pytest_something(object):
+            pass
+
+    pm = pytestconfig.pluginmanager
+    assert pm.parse_hookimpl_opts(Dummy(), "pytest_something") is None
+
+
 class TestWarning(object):
     def test_warn_config(self, testdir):
         testdir.makeconftest(