diff --git a/build.gradle.kts b/build.gradle.kts
index 6ac1293..a5a6812 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -8,7 +8,7 @@ plugins {
 }
 
 group = "org.veupathdb.lib.s3"
-version = "0.4.0+s34k-0.5.0"
+version = "0.5.0+s34k-0.6.0"
 
 repositories {
   mavenLocal()
@@ -36,7 +36,7 @@ dependencies {
   implementation(kotlin("stdlib"))
   implementation("org.slf4j:slf4j-api:1.7.36")
 
-  api("org.veupathdb.lib.s3:s34k:0.5.0")
+  api("org.veupathdb.lib.s3:s34k:0.6.0")
 
   testImplementation("org.junit.jupiter:junit-jupiter:5.8.2")
   testImplementation(kotlin("test"))
diff --git a/src/main/kotlin/org/veupathdb/lib/s3/s34k/core/objects/AbstractS3Object.kt b/src/main/kotlin/org/veupathdb/lib/s3/s34k/core/objects/AbstractS3Object.kt
index e4ae948..8fa0f44 100644
--- a/src/main/kotlin/org/veupathdb/lib/s3/s34k/core/objects/AbstractS3Object.kt
+++ b/src/main/kotlin/org/veupathdb/lib/s3/s34k/core/objects/AbstractS3Object.kt
@@ -14,8 +14,8 @@ import java.time.OffsetDateTime
 @Suppress("unused")
 abstract class AbstractS3Object(
   override val path: String,
-  override val lastModified: OffsetDateTime,
-  override val eTag: String?,
+  override val lastModified: OffsetDateTime?,
+  override val eTag: String,
   override val region: String?,
   override val headers: Headers,
   override val bucket: S3Bucket,