diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7befd6e..ebbf828 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
   - Add `project.config.defaults.enable` to turn off all default settings en masse.
   - Regressions in this PR: #169, #178
 - #175: `devShell`: Add options `benchmark` (to enable benchmark dependencies) and `hoogle` (whether to include Hoogle in development shell)
+- #189: Use `types.str` instead of `types.string` in option types
 
 ## 0.3.0 (May 22, 2023)
 
diff --git a/nix/modules/project/packages/package.nix b/nix/modules/project/packages/package.nix
index bf5d9f3..9d98fc4 100644
--- a/nix/modules/project/packages/package.nix
+++ b/nix/modules/project/packages/package.nix
@@ -24,7 +24,7 @@ in
     };
 
     cabal.executables = mkOption {
-      type = types.nullOr (types.listOf types.string);
+      type = types.nullOr (types.listOf types.str);
       description = ''
         List of executable names found in the cabal file of the package.
         
diff --git a/nix/modules/project/settings/all.nix b/nix/modules/project/settings/all.nix
index a2bb119..6ffb108 100644
--- a/nix/modules/project/settings/all.nix
+++ b/nix/modules/project/settings/all.nix
@@ -45,7 +45,7 @@ in
         if enable then markBroken else unmarkBroken;
     };
     brokenVersions = {
-      type = types.attrsOf types.string;
+      type = types.attrsOf types.str;
       description = ''
         List of versions that are known to be broken.
       '';
@@ -167,21 +167,21 @@ in
       impl = addSetupDepends;
     };
     extraConfigureFlags = {
-      type = types.listOf types.string;
+      type = types.listOf types.str;
       description = ''
         Extra flags to pass to 'cabal configure'
       '';
       impl = appendConfigureFlags;
     };
     extraBuildFlags = {
-      type = types.listOf types.string;
+      type = types.listOf types.str;
       description = ''
         Extra flags to pass to 'cabal build'
       '';
       impl = appendBuildFlags;
     };
     removeConfigureFlags = {
-      type = types.listOf types.string;
+      type = types.listOf types.str;
       description = ''
         Flags to remove from the default flags passed to 'cabal configure'
       '';
@@ -237,7 +237,7 @@ in
         if enable then enableSeparateBinOutput else disableSeparateBinOutput;
     };
     buildTargets = {
-      type = types.listOf types.string;
+      type = types.listOf types.str;
       description = ''
         A list of targets to build.