diff --git a/eden/scm/edenscm/mercurial/configitems.py b/eden/scm/edenscm/mercurial/configitems.py
index c04869e898..965174a356 100644
--- a/eden/scm/edenscm/mercurial/configitems.py
+++ b/eden/scm/edenscm/mercurial/configitems.py
@@ -165,7 +165,6 @@ coreconfigitem("commit", "description-size-limit", default=None)
 coreconfigitem("commit", "extras-size-limit", default=None)
 coreconfigitem("committemplate", ".*", default=None, generic=True)
 coreconfigitem("connectionpool", "lifetime", default=None)
-coreconfigitem("configs", "autogeneratedynamicconfig", default=False)
 coreconfigitem("configs", "generationtime", default=-1)
 coreconfigitem("configs", "loaddynamicconfig", default=False)
 coreconfigitem("configs", "mismatchsampling", default=10000)
diff --git a/eden/scm/edenscm/mercurial/uiconfig.py b/eden/scm/edenscm/mercurial/uiconfig.py
index 1599b9d517..07a344680d 100644
--- a/eden/scm/edenscm/mercurial/uiconfig.py
+++ b/eden/scm/edenscm/mercurial/uiconfig.py
@@ -13,6 +13,7 @@ from __future__ import absolute_import
 import contextlib
 import os
 import random
+import re
 import subprocess
 import time
 from typing import List, Optional, Tuple
@@ -562,15 +563,33 @@ def loaddynamicconfig(ui, path):
 
         hgrcdyn = os.path.join(path, "hgrc.dynamic")
 
-        if ui.configbool("configs", "autogeneratedynamicconfig"):
-            if not os.path.exists(hgrcdyn):
-                try:
-                    ui.debug("synchronously generating dynamic config\n")
-                    subprocess.check_call(["hg", "debugdynamicconfig"])
-                except Exception as ex:
-                    raise error.Abort(
-                        _("unable to generate dynamic Mercurial config: %s") % ex
-                    )
+        # Check the version of the existing generated config. If it doesn't
+        # match the current version, regenerate it immediately.
+        try:
+            with open(hgrcdyn, "r") as f:
+                content = f.read()
+            matches = re.search("^# version=(.*)$", content, re.MULTILINE)
+            version = matches.group(1) if matches else None
+        except IOError:
+            version = None
+
+        if version is None or version != util.version():
+            try:
+                ui.debug(
+                    "synchronously generating dynamic config - new version %s, old version %s\n"
+                    % (util.version(), version)
+                )
+                reponame = ui.config("remotefilelog", "reponame") or ""
+                generatedynamicconfig(ui, reponame, path)
+            except Exception as ex:
+                # TODO: Eventually this should throw an exception, once we're
+                # confident it's reliable.
+                ui.log(
+                    "exceptions",
+                    "unable to generate dynamicconfig",
+                    exception_type="DynamicconfigGeneration",
+                    exception_msg="unable to generate dynamicconfig: %s" % str(ex),
+                )
 
         ui.readconfig(hgrcdyn, path)
 
@@ -617,15 +636,14 @@ def validatedynamicconfig(ui):
     ]
     # Configs that are allowed to be different, usually because they must come
     # from external configuration (like hotfixes).
-    whitelist = [
-        ("extensions", "hotfix"),
-    ]
+    whitelist = [("extensions", "hotfix")]
 
     testrcs = ui.configlist("configs", "testdynamicconfigsubset")
     if testrcs:
         originalrcs.extend(testrcs)
-    issues = ui._uiconfig._rcfg.ensure_location_supersets("hgrc.dynamic",
-            originalrcs, whitelist)
+    issues = ui._uiconfig._rcfg.ensure_location_supersets(
+        "hgrc.dynamic", originalrcs, whitelist
+    )
 
     for section, key, dynamic_value, file_value in issues:
         msg = _("Config mismatch: %s.%s has '%s' (dynamic) vs '%s' (file)\n") % (
@@ -639,20 +657,24 @@ def validatedynamicconfig(ui):
 
         samplerate = ui.configint("configs", "mismatchsampling")
         if random.randint(1, samplerate) == 1:
+            reponame = ui.config("remotefilelog", "reponame")
             ui.log(
                 "config_mismatch",
                 msg,
                 config="%s.%s" % (section, key),
                 expected=file_value,
                 actual=dynamic_value,
+                repo=reponame or "unknown",
             )
 
+
 def applydynamicconfig(ui, reponame):
     if ui.configbool("configs", "loaddynamicconfig"):
         dynamicconfig.applydynamicconfig(ui._uiconfig._rcfg._rcfg, reponame)
 
         validatedynamicconfig(ui)
 
+
 def generatedynamicconfig(ui, reponame, sharedpath):
     if ui.configbool("configs", "loaddynamicconfig"):
         dynamicconfig.generatedynamicconfig(reponame, sharedpath)
diff --git a/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/Cargo.toml b/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/Cargo.toml
index 6224bb97c2..2772bd1cf7 100644
--- a/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/Cargo.toml
+++ b/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/Cargo.toml
@@ -10,6 +10,7 @@ cpython-ext = { path = "../../../../lib/cpython-ext", default-features = false }
 dynamicconfig = { path = "../../../../lib/dynamicconfig" }
 configparser = { path = "../../../../lib/configparser" }
 pyconfigparser = { path = "../pyconfigparser" }
+version = { path = "../../../../lib/version" }
 
 [features]
 python2 = ["cpython/python27-sys", "cpython-ext/python2"]
diff --git a/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/src/lib.rs b/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/src/lib.rs
index db85d8e6d8..1cda1169a0 100644
--- a/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/src/lib.rs
+++ b/eden/scm/edenscmnative/bindings/modules/pydynamicconfig/src/lib.rs
@@ -9,7 +9,6 @@
 
 use std::fs;
 
-use anyhow::{format_err, Error};
 use cpython::*;
 use cpython_ext::{error::ResultPyErrExt, PyNone, PyPathBuf};
 
@@ -68,7 +67,8 @@ fn generatedynamicconfig(
         .map_pyerr(py)?;
     let config_str = config.to_string();
     let config_str = format!(
-        "# Generated by `hg debugdynamicconfig` - DO NOT MODIFY\n{}",
+        "# version={}\n# Generated by `hg debugdynamicconfig` - DO NOT MODIFY\n{}",
+        ::version::VERSION,
         config_str
     );
 
diff --git a/eden/scm/lib/hgcommands/src/commands.rs b/eden/scm/lib/hgcommands/src/commands.rs
index 3f4f0a425b..0921ffcde4 100644
--- a/eden/scm/lib/hgcommands/src/commands.rs
+++ b/eden/scm/lib/hgcommands/src/commands.rs
@@ -298,7 +298,8 @@ pub fn debugdynamicconfig(_opts: NoOpts, _io: &mut IO, repo: Repo) -> Result<u8>
     let config = Generator::new(repo_name)?.execute()?;
     let config_str = config.to_string();
     let config_str = format!(
-        "# Generated by `hg debugdynamicconfig` - DO NOT MODIFY\n{}",
+        "# version={}\n# Generated by `hg debugdynamicconfig` - DO NOT MODIFY\n{}",
+        ::version::VERSION,
         config_str
     );
 
diff --git a/eden/scm/tests/test-debugdynamicconfig.t b/eden/scm/tests/test-debugdynamicconfig.t
index 13f1e7588b..cc832c4b8d 100644
--- a/eden/scm/tests/test-debugdynamicconfig.t
+++ b/eden/scm/tests/test-debugdynamicconfig.t
@@ -16,6 +16,7 @@ Verify it can be manually generated
 
   $ hg debugdynamicconfig
   $ cat .hg/hgrc.dynamic
+  # version=4.4.2* (glob)
   # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
   [section]
   key=value
@@ -27,10 +28,9 @@ Verify it can be automatically synchronously generated
 
   $ rm .hg/hgrc.dynamic
   $ hg config section.key
-  [1]
-  $ hg config section.key --config configs.autogeneratedynamicconfig=True
   value
   $ cat .hg/hgrc.dynamic
+  # version=4.4.2* (glob)
   # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
   [section]
   key=value
@@ -51,6 +51,7 @@ Verify it can be automatically asynchronously regenerated
   $ hg config section2.key2
   value2
   $ cat .hg/hgrc.dynamic
+  # version=4.4.2* (glob)
   # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
   [section]
   key=value
@@ -83,6 +84,7 @@ Verify we generate and load from a shared repo
   $ test -f .hg/hgrc.dynamic
   [1]
   $ cat ../shared/.hg/hgrc.dynamic
+  # version=4.4.2* (glob)
   # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
   [section]
   key=value
@@ -93,6 +95,33 @@ Verify we generate and load from a shared repo
   $ hg config section.key
   value
 
+Verify we regenerate configs if the Mercurial version differs
+  $ cat > ../shared/.hg/hgrc.dynamic <<EOF
+  > # version=1
+  > [section3]
+  > key3=value3
+  > EOF
+  $ hg config section3.key3
+  [1]
+  $ hg config section.key
+  value
+  $ cat ../shared/.hg/hgrc.dynamic
+  # version=4.4.2* (glob)
+  # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
+  [section]
+  key=value
+  
+  [section2]
+  key2=value2
+  
+Verify we don't regenerate configs if the Mercurial version hasn't changed
+  $ cat >> ../shared/.hg/hgrc.dynamic <<EOF
+  > [section3]
+  > key3=value3
+  > EOF
+  $ hg config section3.key3
+  value3
+
 Verify we load dynamicconfigs during clone
   $ newserver server
   $ cd $TESTTMP
@@ -109,6 +138,7 @@ Verify we load dynamicconfigs during clone
   Hook ran!
   Hook ran!
   $ cat client2/.hg/hgrc.dynamic
+  # version=4.4.2* (glob)
   # Generated by `hg debugdynamicconfig` - DO NOT MODIFY
   [hooks]
   pretxnclose=echo "Hook ran!"