diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9362827..dc11b03 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,11 +10,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Checkout Code
-        uses: actions/checkout@v5
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
-      - name: Set up Java
-        uses: actions/setup-java@v5
+      - uses: actions/setup-java@de7274f081f381c8f8158605e0321c36c376e2e6 # v6.0.1
         with:
           distribution: 'temurin'
           java-version: '8'
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 960613d..2d92f0b 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -7,11 +7,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Checkout Code
-        uses: actions/checkout@v5
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
-      - name: Set up Java
-        uses: actions/setup-java@v5
+      - uses: actions/setup-java@de7274f081f381c8f8158605e0321c36c376e2e6 # v6.0.1
         with:
           distribution: 'temurin'
           java-version: '8'
diff --git a/.github/workflows/github-release.yml b/.github/workflows/github-release.yml
index 816ab46..4eae0f7 100644
--- a/.github/workflows/github-release.yml
+++ b/.github/workflows/github-release.yml
@@ -17,8 +17,7 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
       - name: Create GitHub Release
         env:
diff --git a/pom.xml b/pom.xml
index 113d78a..32bf489 100644
--- a/pom.xml
+++ b/pom.xml
@@ -8,7 +8,7 @@
     <artifactId>j2mod</artifactId>
     <name>j2mod</name>
     <url>https://github.com/OpenEMS/j2mod</url>
-    <version>3.4.0-openems.1</version>
+    <version>3.4.0-openems.2-SNAPSHOT</version>
     <description>A Modbus TCP/UDP/Serial Master and Slave implementation</description>
 
     <packaging>bundle</packaging>
diff --git a/src/main/java/com/ghgande/j2mod/modbus/io/ModbusSerialTransport.java b/src/main/java/com/ghgande/j2mod/modbus/io/ModbusSerialTransport.java
index 7abd4cf..9ed09b1 100644
--- a/src/main/java/com/ghgande/j2mod/modbus/io/ModbusSerialTransport.java
+++ b/src/main/java/com/ghgande/j2mod/modbus/io/ModbusSerialTransport.java
@@ -56,12 +56,12 @@ public abstract class ModbusSerialTransport extends AbstractModbusTransport {
     /**
      * The number of nanoseconds there is in a millisecond
      */
-    private static final int NS_IN_A_MS = 1_000_000;
+    private static final double NS_IN_A_MS = 1_000_000.0;
 
     /**
      * The number of nanoseconds there is in a second
      */
-    private static final int NS_IN_A_SEC = 1_000_000_000;
+    private static final double NS_IN_A_SEC = 1_000_000_000.0;
 
     private static final String CANNOT_READ_FROM_SERIAL_PORT = "Cannot read from serial port";
     private static final String COMM_PORT_IS_NOT_VALID_OR_NOT_OPEN = "Comm port is not valid or not open";
@@ -121,7 +121,7 @@ private void waitForTransmission(long startTime, double transmissionTimeNanos) {
         if (transmissionTimeNanos >= NS_IN_A_MS) {
             try {
                 final long adjustedDelay = (long) (transmissionTimeNanos * LONG_DELAY_FUDGE_FACTOR);
-                final long sleepMillis = adjustedDelay / NS_IN_A_MS;
+                final long sleepMillis = (long) (adjustedDelay / NS_IN_A_MS);
                 final int sleepNanos = (int) (adjustedDelay % NS_IN_A_MS);
 
                 Thread.sleep(sleepMillis, sleepNanos);
@@ -637,7 +637,7 @@ void waitBetweenFrames(int transDelayMS, long lastTransactionTimestamp) {
             int delay = getInterFrameDelay() / 1000;
 
             // How long since the last message we received
-            long gapSinceLastMessage = (System.nanoTime() - lastTransactionTimestamp) / NS_IN_A_MS;
+            long gapSinceLastMessage = (long) ((System.nanoTime() - lastTransactionTimestamp) / NS_IN_A_MS);
             if (delay > gapSinceLastMessage) {
                 long sleepTime = delay - gapSinceLastMessage;