diff --git a/CHANGES b/CHANGES
index 3077ee31c..d76c26f78 100644
--- a/CHANGES
+++ b/CHANGES
@@ -36,6 +36,9 @@ Bugs fixed
 * #908: On Python 3, handle error messages from LaTeX correctly in the pngmath
   extension.
 
+* #943: In autosummary, recognize "first sentences" to pull from the docstring
+  if they contain uppercase letters.
+
 Documentation
 -------------
 
diff --git a/sphinx/ext/autosummary/__init__.py b/sphinx/ext/autosummary/__init__.py
index a73e79f5b..af0fa65cf 100644
--- a/sphinx/ext/autosummary/__init__.py
+++ b/sphinx/ext/autosummary/__init__.py
@@ -199,7 +199,6 @@ class Autosummary(Directive):
         nodes = self.get_table(items)
 
         if 'toctree' in self.options:
-            suffix = env.config.source_suffix
             dirname = posixpath.dirname(env.docname)
 
             tree_prefix = self.options['toctree'].strip()
@@ -276,7 +275,7 @@ class Autosummary(Directive):
 
             while doc and not doc[0].strip():
                 doc.pop(0)
-            m = re.search(r"^([A-Z][^A-Z]*?\.\s)", " ".join(doc).strip())
+            m = re.search(r"^([A-Z].*?\.)(?:\s|$)", " ".join(doc).strip())
             if m:
                 summary = m.group(1).strip()
             elif doc: