diff --git a/CHANGELOG.md b/CHANGELOG.md
index 930dabd..c2f9e6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 
+## [v4.3.1] - 2022-05-011
+
+### Changed
+ - Support to expose metrics in Prometheus format (http://localhost:19090/metrics).
+ - Changed the response time unit from nano to milliseconds.
+
 ## [v4.3.0] - 2022-05-011
 
 ### Added
diff --git a/Cargo.lock b/Cargo.lock
index a8fd689..817b249 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1441,7 +1441,7 @@ checksum = "e604eb7b43c06650e854be16a2a03155743d3752dd1c943f6829e26b7a36e382"
 
 [[package]]
 name = "tsample"
-version = "4.3.0"
+version = "4.3.1"
 dependencies = [
  "anyhow",
  "chrono",
diff --git a/Cargo.toml b/Cargo.toml
index 44ffcf6..058e20c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tsample"
-version = "4.3.0"
+version = "4.3.1"
 authors = ["xudesheng <xudesheng@gmail.com>"]
 edition = "2021"
 readme = "README.md"
diff --git a/src/prometheus.rs b/src/prometheus.rs
index 6d1dcfe..6b2139a 100644
--- a/src/prometheus.rs
+++ b/src/prometheus.rs
@@ -59,7 +59,7 @@ pub async fn prometheus_thread(
                         if field.0 == "ResponseTime" {
                             response_time
                                 .with_label_values(&[&write_spec.measurement])
-                                .observe(value);
+                                .observe(value / 1000000.0); // convert to milliseconds from nanoseconds
                         } else {
                             let map = gauge_map.read().expect("Read Lock poisoned.");
                             let mut label_values: Vec<&str> = vec![];