diff --git a/jedi/parser/python/tree.py b/jedi/parser/python/tree.py
index 91c5c165..f590f72c 100644
--- a/jedi/parser/python/tree.py
+++ b/jedi/parser/python/tree.py
@@ -1230,7 +1230,15 @@ class Param(PythonBaseNode):
 
     @property
     def position_nr(self):
-        return self.parent.children.index(self) - 1
+        index = self.parent.children.index(self)
+        try:
+            keyword_only_index = self.parent.children.index('*')
+            if index > keyword_only_index:
+                # Skip the ` *, `
+                index -= 2
+        except ValueError:
+            pass
+        return index - 1
 
     def get_parent_function(self):
         return search_ancestor(self, ('funcdef', 'lambda'))
diff --git a/test/completion/pep0484_basic.py b/test/completion/pep0484_basic.py
index b944cd1d..0230d375 100644
--- a/test/completion/pep0484_basic.py
+++ b/test/completion/pep0484_basic.py
@@ -158,3 +158,10 @@ Y = int
 def just_because_we_can(x: "flo" + "at"):
     #? float()
     x
+
+
+def keyword_only(a: str, *, b: str):
+    #? ['startswith']
+    a.startswi
+    #? ['startswith']
+    b.startswi