diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## [0.5.1.1] - 2024-08-08
+
+### Changed
+
+* Fixed a bug in which a `setting` with only a default `value` was considered invalid.
+
 ## [0.5.1.0] - 2024-08-08
 
 ### Removed
diff --git a/opt-env-conf.cabal b/opt-env-conf.cabal
--- a/opt-env-conf.cabal
+++ b/opt-env-conf.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           opt-env-conf
-version:        0.5.1.0
+version:        0.5.1.1
 synopsis:       Settings parsing for Haskell: command-line arguments, environment variables, and configuration values.
 homepage:       https://github.com/NorfairKing/opt-env-conf#readme
 bug-reports:    https://github.com/NorfairKing/opt-env-conf/issues
diff --git a/src/OptEnvConf/Lint.hs b/src/OptEnvConf/Lint.hs
--- a/src/OptEnvConf/Lint.hs
+++ b/src/OptEnvConf/Lint.hs
@@ -288,7 +288,8 @@
                 isNothing settingSwitchValue,
                 not settingTryOption,
                 isNothing settingEnvVars,
-                isNothing settingConfigVals
+                isNothing settingConfigVals,
+                isNothing settingDefaultValue
               ]
           )
           $ validationTFailure LintErrorEmptySetting