diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index ab943b6..583c444 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -5,6 +5,10 @@ repos:
       - id: trailing-whitespace
       - id: end-of-file-fixer
       - id: check-yaml
+        # This is the stock Synapse sample homeserver.yaml (mostly commented-out
+        # docs). prek's stricter YAML parser (serde-saphyr, since v0.4.6) rejects
+        # its long runs of consecutive comment lines in several places.
+        exclude: '^etc/services/synapse/config/homeserver\.yaml$'
       - id: check-merge-conflict
       - id: check-added-large-files
         args: ['--maxkb=1024']
diff --git a/mise.toml b/mise.toml
index 83478fe..b30dc9c 100644
--- a/mise.toml
+++ b/mise.toml
@@ -1,5 +1,5 @@
 [tools]
-prek = "0.4.5"
+prek = "0.4.6"
 
 [settings]
 # Disable automatic trust prompts - we trust this config