diff --git a/jedi/plugins/pytest.py b/jedi/plugins/pytest.py
index 7ae2194d..910f540c 100644
--- a/jedi/plugins/pytest.py
+++ b/jedi/plugins/pytest.py
@@ -1,3 +1,4 @@
+from parso.python.tree import search_ancestor
 from jedi._compatibility import FileNotFoundError
 from jedi.inference.cache import inference_state_method_cache
 from jedi.inference.imports import load_module_from_path
@@ -32,23 +33,25 @@ def infer_anonymous_param(func):
             return function_context.get_return_values()
 
     def wrapper(param_name):
-        module = param_name.get_root_context()
-        fixtures = _goto_pytest_fixture(module, param_name.string_name)
-        if fixtures:
-            return ValueSet.from_sets(
-                get_returns(value)
-                for fixture in fixtures
-                for value in fixture.infer()
-            )
+        if _is_a_pytest_param(param_name):
+            module = param_name.get_root_context()
+            fixtures = _goto_pytest_fixture(module, param_name.string_name)
+            if fixtures:
+                return ValueSet.from_sets(
+                    get_returns(value)
+                    for fixture in fixtures
+                    for value in fixture.infer()
+                )
         return func(param_name)
     return wrapper
 
 
 def goto_anonymous_param(func):
     def wrapper(param_name):
-        names = _goto_pytest_fixture(param_name.get_root_context(), param_name.string_name)
-        if names:
-            return names
+        if _is_a_pytest_param(param_name):
+            names = _goto_pytest_fixture(param_name.get_root_context(), param_name.string_name)
+            if names:
+                return names
         return func(param_name)
     return wrapper
 
@@ -56,8 +59,7 @@ def goto_anonymous_param(func):
 def complete_param_names(func):
     def wrapper(context, func_name, decorator_nodes):
         module_context = context.get_root_context()
-        if func_name.startswith('test_') \
-                or any('fixture' in n.get_code() for n in decorator_nodes):
+        if _is_pytest_func(func_name, decorator_nodes):
             names = []
             for module_context in _iter_pytest_modules(module_context):
                 names += FixtureFilter(module_context).values()
@@ -74,6 +76,23 @@ def _goto_pytest_fixture(module_context, name):
             return names
 
 
+def _is_a_pytest_param(param_name):
+    """
+    Pytest params are either in a `test_*` function or have a pytest fixture
+    with the decorator @pytest.fixture.
+
+    This is a heuristic and will work in most cases.
+    """
+    funcdef = search_ancestor(param_name.tree_name, 'funcdef')
+    decorators = funcdef.get_decorators()
+    return _is_pytest_func(funcdef.name.value, decorators)
+
+
+def _is_pytest_func(func_name, decorator_nodes):
+    return func_name.startswith('test_') \
+        or any('fixture' in n.get_code() for n in decorator_nodes)
+
+
 @inference_state_method_cache()
 def _iter_pytest_modules(module_context):
     yield module_context
diff --git a/test/completion/pytest.py b/test/completion/pytest.py
index 345fa34d..eed0217e 100644
--- a/test/completion/pytest.py
+++ b/test/completion/pytest.py
@@ -47,6 +47,24 @@ def test_x(MyClassFixture):
     #?
     MyClassFixture
 
+#? 15
+def lala(my_fixture):
+    pass
+
+@pytest.fixture
+#? 15 str()
+def lala(my_fixture):
+    pass
+
+#! 15 ['param my_fixture']
+def lala(my_fixture):
+    pass
+
+@pytest.fixture
+#! 15 ['def my_fixture']
+def lala(my_fixture):
+    pass
+
 # -----------------
 # completion
 # -----------------