diff --git a/compute/vm-image-spec-bookworm.yaml b/compute/vm-image-spec-bookworm.yaml
index 568f0b0444..ff4c3387d9 100644
--- a/compute/vm-image-spec-bookworm.yaml
+++ b/compute/vm-image-spec-bookworm.yaml
@@ -44,6 +44,11 @@ shutdownHook: |
 files:
   - filename: compute_ctl-sudoers
     content: |
+      # Reverse hostname lookup doesn't currently work, and isn't needed anyway when all
+      # the rules use ALL as the hostname. Avoid the pointless lookups and the "unable to
+      # resolve host" log messages that they generate.
+      Defaults !fqdn
+      
       # Allow postgres user (which is what compute_ctl runs as) to run /neonvm/bin/resize-swap
       # and /neonvm/bin/set-disk-quota as root without requiring entering a password (NOPASSWD),
       # regardless of hostname (ALL)
diff --git a/compute/vm-image-spec-bullseye.yaml b/compute/vm-image-spec-bullseye.yaml
index 6617c98599..c001040bc9 100644
--- a/compute/vm-image-spec-bullseye.yaml
+++ b/compute/vm-image-spec-bullseye.yaml
@@ -44,6 +44,11 @@ shutdownHook: |
 files:
   - filename: compute_ctl-sudoers
     content: |
+      # Reverse hostname lookup doesn't currently work, and isn't needed anyway when all
+      # the rules use ALL as the hostname. Avoid the pointless lookups and the "unable to
+      # resolve host" log messages that they generate.
+      Defaults !fqdn
+      
       # Allow postgres user (which is what compute_ctl runs as) to run /neonvm/bin/resize-swap
       # and /neonvm/bin/set-disk-quota as root without requiring entering a password (NOPASSWD),
       # regardless of hostname (ALL)