diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -1307,12 +1307,22 @@ def _exceptionwarning(ui):
             + b'\n'
         )
     sysversion = pycompat.sysbytes(sys.version).replace(b'\n', b'')
+
+    def ext_with_ver(x):
+        ext = x[0]
+        ver = extensions.moduleversion(x[1])
+        if ver:
+            ext += b' ' + ver
+        return ext
+
     warning += (
         (_(b"** Python %s\n") % sysversion)
         + (_(b"** Mercurial Distributed SCM (version %s)\n") % util.version())
         + (
             _(b"** Extensions loaded: %s\n")
-            % b", ".join([x[0] for x in sorted(extensions.extensions())])
+            % b", ".join(
+                [ext_with_ver(x) for x in sorted(extensions.extensions())]
+            )
         )
     )
     return warning
diff --git a/tests/test-extension.t b/tests/test-extension.t
--- a/tests/test-extension.t
+++ b/tests/test-extension.t
@@ -1421,7 +1421,7 @@ No declared supported version, extension
   ** If that fixes the bug please report it to the extension author.
   ** Python * (glob)
   ** Mercurial Distributed SCM * (glob)
-  ** Extensions loaded: throw
+  ** Extensions loaded: throw 1.0.0
 
 empty declaration of supported version, extension complains (but doesn't choke if
 the value is improperly a str instead of bytes):
@@ -1433,7 +1433,7 @@ the value is improperly a str instead of
   ** If that fixes the bug please report it to the extension author.
   ** Python * (glob)
   ** Mercurial Distributed SCM (*) (glob)
-  ** Extensions loaded: throw
+  ** Extensions loaded: throw 1.0.0
 
 If the extension specifies a buglink, show that (but don't choke if the value is
 improperly a str instead of bytes):
@@ -1447,7 +1447,7 @@ improperly a str instead of bytes):
   ** If that fixes the bug please report it to http://example.com/bts
   ** Python * (glob)
   ** Mercurial Distributed SCM (*) (glob)
-  ** Extensions loaded: throw
+  ** Extensions loaded: throw 1.0.0
 
 If the extensions declare outdated versions, accuse the older extension first:
   $ echo "from mercurial import util" >> older.py
@@ -1464,7 +1464,7 @@ If the extensions declare outdated versi
   ** If that fixes the bug please report it to the extension author.
   ** Python * (glob)
   ** Mercurial Distributed SCM (version 2.2)
-  ** Extensions loaded: older, throw
+  ** Extensions loaded: older, throw 1.0.0
 
 One extension only tested with older, one only with newer versions:
   $ echo "util.version = lambda:b'2.1'" >> older.py
@@ -1478,7 +1478,7 @@ One extension only tested with older, on
   ** If that fixes the bug please report it to the extension author.
   ** Python * (glob)
   ** Mercurial Distributed SCM (version 2.1)
-  ** Extensions loaded: older, throw
+  ** Extensions loaded: older, throw 1.0.0
 
 Older extension is tested with current version, the other only with newer:
   $ echo "util.version = lambda:b'1.9.3'" >> older.py
@@ -1492,7 +1492,7 @@ Older extension is tested with current v
   ** If that fixes the bug please report it to http://example.com/bts
   ** Python * (glob)
   ** Mercurial Distributed SCM (version 1.9.3)
-  ** Extensions loaded: older, throw
+  ** Extensions loaded: older, throw 1.0.0
 
 Ability to point to a different point
   $ hg --config extensions.throw=throw.py --config extensions.older=older.py \
@@ -1501,7 +1501,7 @@ Ability to point to a different point
   ** Your Local Goat Lenders
   ** Python * (glob)
   ** Mercurial Distributed SCM (*) (glob)
-  ** Extensions loaded: older, throw
+  ** Extensions loaded: older, throw 1.0.0
 
 Declare the version as supporting this hg version, show regular bts link:
   $ hgver=`hg debuginstall -T '{hgver}'`
@@ -1516,7 +1516,7 @@ Declare the version as supporting this h
   ** https://mercurial-scm.org/wiki/BugTracker
   ** Python * (glob)
   ** Mercurial Distributed SCM (*) (glob)
-  ** Extensions loaded: throw
+  ** Extensions loaded: throw 1.0.0
 
 Patch version is ignored during compatibility check
   $ echo "testedwith = b'3.2'" >> throw.py
@@ -1528,7 +1528,7 @@ Patch version is ignored during compatib
   ** https://mercurial-scm.org/wiki/BugTracker
   ** Python * (glob)
   ** Mercurial Distributed SCM (*) (glob)
-  ** Extensions loaded: throw
+  ** Extensions loaded: throw 1.0.0
 
 Test version number support in 'hg version':
   $ echo '__version__ = (1, 2, 3)' >> throw.py