diff --git a/core/src/main/java/org/testcontainers/containers/GenericContainer.java b/core/src/main/java/org/testcontainers/containers/GenericContainer.java
index 211ad2f59cb..63191998db4 100644
--- a/core/src/main/java/org/testcontainers/containers/GenericContainer.java
+++ b/core/src/main/java/org/testcontainers/containers/GenericContainer.java
@@ -77,6 +77,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -118,7 +119,7 @@ public class GenericContainer<SELF extends GenericContainer<SELF>>
      * Default settings
      */
     @NonNull
-    private List<Integer> exposedPorts = new ArrayList<>();
+    private LinkedHashSet<Integer> exposedPorts = new LinkedHashSet<>();
 
     @NonNull
     private List<String> portBindings = new ArrayList<>();
@@ -256,6 +257,16 @@ public void setImage(Future<String> image) {
         this.image = new RemoteDockerImage(image);
     }
 
+    @Override
+    public List<Integer> getExposedPorts() {
+        return new ArrayList<>(exposedPorts);
+    }
+
+    @Override
+    public void setExposedPorts(List<Integer> exposedPorts) {
+        this.exposedPorts = new LinkedHashSet<>(exposedPorts);
+    }
+
     /**
      * @see #dependsOn(Iterable)
      */
@@ -672,8 +683,9 @@ protected void containerIsStopped(InspectContainerResponse containerInfo) {
     @Deprecated
     protected Integer getLivenessCheckPort() {
         // legacy implementation for backwards compatibility
-        if (exposedPorts.size() > 0) {
-            return getMappedPort(exposedPorts.get(0));
+        Iterator<Integer> exposedPortsIterator = exposedPorts.iterator();
+        if (exposedPortsIterator.hasNext()) {
+            return getMappedPort(exposedPortsIterator.next());
         } else if (portBindings.size() > 0) {
             return Integer.valueOf(PortBinding.parse(portBindings.get(0)).getBinding().getHostPortSpec());
         } else {
diff --git a/core/src/test/java/org/testcontainers/junit/GenericContainerRuleTest.java b/core/src/test/java/org/testcontainers/junit/GenericContainerRuleTest.java
index 6c51713b6b1..3170e34a3ec 100644
--- a/core/src/test/java/org/testcontainers/junit/GenericContainerRuleTest.java
+++ b/core/src/test/java/org/testcontainers/junit/GenericContainerRuleTest.java
@@ -379,6 +379,15 @@ public void addExposedPortAfterWithExposedPortsTest() {
         assertTrue("addExposedPort should be exposed", redis.getExposedPorts().contains(8987));
     }
 
+    @Test
+    public void addingExposedPortTwiceShouldNotFail() {
+        redis.addExposedPort(8987);
+        redis.addExposedPort(8987);
+        assertThat("Both ports should be exposed", redis.getExposedPorts().size(), equalTo(2)); // 2 ports = de-duplicated port 8897 and original port 6379
+        assertTrue("withExposedPort should be exposed", redis.getExposedPorts().contains(REDIS_PORT));
+        assertTrue("addExposedPort should be exposed", redis.getExposedPorts().contains(8987));
+    }
+
     @Test
     public void sharedMemorySetTest() {
         try (GenericContainer containerWithSharedMemory = new GenericContainer()