diff --git a/fire/docstrings.py b/fire/docstrings.py
index e173d192..244f5769 100644
--- a/fire/docstrings.py
+++ b/fire/docstrings.py
@@ -295,9 +295,8 @@ def _is_arg_name(name):
   """Returns whether name is a valid arg name.
 
   This is used to prevent multiple words (plaintext) from being misinterpreted
-  as an argument name. So if ":" appears in the middle of a line in a docstring,
-  we don't accidentally interpret the first half of that line as a single arg
-  name.
+  as an argument name. Any line that doesn't match the pattern for a valid
+  argument is treated as not being an argument.
 
   Args:
     name: The name of the potential arg.
@@ -305,9 +304,11 @@ def _is_arg_name(name):
     True if name looks like an arg name, False otherwise.
   """
   name = name.strip()
-  return (name
-          and ' ' not in name
-          and ':' not in name)
+  # arg_pattern is a letter or underscore followed by
+  # zero or more letters, numbers, or underscores.
+  arg_pattern = r'^[a-zA-Z_]\w*$'
+  re.match(arg_pattern, name)
+  return re.match(arg_pattern, name) is not None
 
 
 def _as_arg_name_and_type(text):
@@ -390,6 +391,7 @@ def _consume_google_args_line(line_info, state):
         arg = _get_or_create_arg_by_name(state, arg_name)
         arg.type.lines.append(type_str)
         arg.description.lines.append(second.strip())
+        state.current_arg = arg
       else:
         if state.current_arg:
           state.current_arg.description.lines.append(split_line[0])
diff --git a/fire/docstrings_test.py b/fire/docstrings_test.py
index 8b1d7685..fcb1b115 100644
--- a/fire/docstrings_test.py
+++ b/fire/docstrings_test.py
@@ -142,6 +142,32 @@ def test_google_format_typed_args_and_returns(self):
     )
     self.assertEqual(expected_docstring_info, docstring_info)
 
+  def test_google_format_multiline_arg_description(self):
+    docstring = """Docstring summary.
+
+    This is a longer description of the docstring. It spans multiple lines, as
+    is allowed.
+
+    Args:
+        param1 (int): The first parameter.
+        param2 (str): The second parameter. This has a lot of text, enough to
+        cover two lines.
+    """
+    docstring_info = docstrings.parse(docstring)
+    expected_docstring_info = DocstringInfo(
+        summary='Docstring summary.',
+        description='This is a longer description of the docstring. It spans '
+        'multiple lines, as\nis allowed.',
+        args=[
+            ArgInfo(name='param1', type='int',
+                    description='The first parameter.'),
+            ArgInfo(name='param2', type='str',
+                    description='The second parameter. This has a lot of text, '
+                                'enough to cover two lines.'),
+        ],
+    )
+    self.assertEqual(expected_docstring_info, docstring_info)
+
   def test_rst_format_typed_args_and_returns(self):
     docstring = """Docstring summary.
 
@@ -205,6 +231,35 @@ def test_numpy_format_typed_args_and_returns(self):
     )
     self.assertEqual(expected_docstring_info, docstring_info)
 
+  def test_numpy_format_multiline_arg_description(self):
+    docstring = """Docstring summary.
+
+    This is a longer description of the docstring. It spans across multiple
+    lines.
+
+    Parameters
+    ----------
+    param1 : int
+        The first parameter.
+    param2 : str
+        The second parameter. This has a lot of text, enough to cover two
+        lines.
+    """
+    docstring_info = docstrings.parse(docstring)
+    expected_docstring_info = DocstringInfo(
+        summary='Docstring summary.',
+        description='This is a longer description of the docstring. It spans '
+        'across multiple\nlines.',
+        args=[
+            ArgInfo(name='param1', type='int',
+                    description='The first parameter.'),
+            ArgInfo(name='param2', type='str',
+                    description='The second parameter. This has a lot of text, '
+                                'enough to cover two lines.'),
+        ],
+    )
+    self.assertEqual(expected_docstring_info, docstring_info)
+
   def test_multisection_docstring(self):
     docstring = """Docstring summary.