diff --git a/build.gradle b/build.gradle
index 261dfabf0412..1387ab8effbe 100644
--- a/build.gradle
+++ b/build.gradle
@@ -36,7 +36,7 @@ buildscript {
     classpath 'org.revapi:gradle-revapi:1.8.0'
     classpath 'com.gorylenko.gradle-git-properties:gradle-git-properties:2.5.7'
     classpath 'com.palantir.gradle.gitversion:gradle-git-version:4.3.0'
-    classpath 'org.openapitools:openapi-generator-gradle-plugin:7.21.0'
+    classpath 'org.openapitools:openapi-generator-gradle-plugin:7.22.0'
   }
 }
 
@@ -581,7 +581,7 @@ project(':iceberg-aws') {
   }
 
   // TODO delete once s3-signer-open-api.yaml is removed
-  def s3SignerSpec = "$projectDir/src/main/resources/s3-signer-open-api.yaml"
+  def s3SignerSpec = layout.projectDirectory.file("src/main/resources/s3-signer-open-api.yaml")
   tasks.register('validateS3SignerSpec', org.openapitools.generator.gradle.plugin.tasks.ValidateTask) {
     inputSpec.set(s3SignerSpec)
     recommend.set(true)
@@ -1140,7 +1140,7 @@ project(':iceberg-open-api') {
             .collectEntries { k, v -> { [(k):v, (k.replaceFirst("rck.", "")):v] }} // strip prefix
   }
 
-  def restCatalogSpec = "$projectDir/rest-catalog-open-api.yaml"
+  def restCatalogSpec = layout.projectDirectory.file("rest-catalog-open-api.yaml")
   tasks.register('validateRESTCatalogSpec', org.openapitools.generator.gradle.plugin.tasks.ValidateTask) {
     inputSpec.set(restCatalogSpec)
     recommend.set(true)