diff --git a/docs/release-notes.rst b/docs/release-notes.rst
index 6b898fc6..ce2b9c7e 100644
--- a/docs/release-notes.rst
+++ b/docs/release-notes.rst
@@ -5,6 +5,7 @@ Release Notes
 .. toctree::
    :maxdepth: 2
 
+   release-notes/version-4.4.20
    release-notes/version-4.4.19
    release-notes/version-4.4.18
    release-notes/version-4.4.17
diff --git a/docs/release-notes/version-4.4.20.rst b/docs/release-notes/version-4.4.20.rst
new file mode 100644
index 00000000..5f69c916
--- /dev/null
+++ b/docs/release-notes/version-4.4.20.rst
@@ -0,0 +1,18 @@
+==============
+Version 4.4.20
+==============
+
+Version 4.4.20 of mod_wsgi can be obtained from:
+
+  https://codeload.github.com/GrahamDumpleton/mod_wsgi/tar.gz/4.4.20
+
+For details on the availability of Windows binaries see:
+
+  https://github.com/GrahamDumpleton/mod_wsgi/tree/master/win32
+
+Bugs Fixed
+----------
+
+1. Post mortem debugger would fail if the exception was raised during
+yielding of items from a WSGI application, or inside of any ``close()``
+callable of an iterator returned from the WSGI application.
diff --git a/src/server/__init__.py b/src/server/__init__.py
index 124a6924..9df57c15 100644
--- a/src/server/__init__.py
+++ b/src/server/__init__.py
@@ -1117,7 +1117,7 @@ def __iter__(self):
             for item in self.generator:
                 yield item
         except Exception:
-            self.debug_exception()
+            self.run_post_mortem()
             raise
 
     def close(self):
@@ -1125,7 +1125,7 @@ def close(self):
             if hasattr(self.generator, 'close'):
                 return self.generator.close()
         except Exception:
-            self.debug_exception()
+            self.run_post_mortem()
             raise
 
 class RequestRecorder(object):
diff --git a/src/server/wsgi_version.h b/src/server/wsgi_version.h
index b6e5dde7..87657369 100644
--- a/src/server/wsgi_version.h
+++ b/src/server/wsgi_version.h
@@ -25,8 +25,8 @@
 
 #define MOD_WSGI_MAJORVERSION_NUMBER 4
 #define MOD_WSGI_MINORVERSION_NUMBER 4
-#define MOD_WSGI_MICROVERSION_NUMBER 19
-#define MOD_WSGI_VERSION_STRING "4.4.19"
+#define MOD_WSGI_MICROVERSION_NUMBER 20
+#define MOD_WSGI_VERSION_STRING "4.4.20"
 
 /* ------------------------------------------------------------------------- */