diff --git a/gradle.lockfile b/gradle.lockfile
index a20d0b75..7f013a11 100644
--- a/gradle.lockfile
+++ b/gradle.lockfile
@@ -10,7 +10,7 @@ javax.validation:validation-api:2.0.1.Final=compileClasspath,runtimeClasspath
 org.embulk:embulk-spi:0.11=compileClasspath
 org.embulk:embulk-util-config:0.5.0=compileClasspath,runtimeClasspath
 org.embulk:embulk-util-rubytime:0.4.0=compileClasspath,runtimeClasspath
-org.embulk:embulk-util-timestamp:0.3.0=compileClasspath,runtimeClasspath
+org.embulk:embulk-util-timestamp:0.3.1=compileClasspath,runtimeClasspath
 org.msgpack:msgpack-core:0.8.24=compileClasspath
 org.slf4j:slf4j-api:2.0.7=compileClasspath
 empty=
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c65cb1d8..10fa749e 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -13,7 +13,7 @@ validation-api = "2.0.1.Final"
 # We choose Jackson with the latest patch release of the latest open branch.
 jackson = "2.16.2"
 
-embulk-util-timestamp = "0.3.0"
+embulk-util-timestamp = "0.3.1"
 
 checkstyle = "9.3"