diff --git a/api/src/main/java/org/apache/cloudstack/api/command/admin/vm/ImportUnmanagedInstanceCmd.java b/api/src/main/java/org/apache/cloudstack/api/command/admin/vm/ImportUnmanagedInstanceCmd.java
index fd18e44754a4..8d7db1294503 100644
--- a/api/src/main/java/org/apache/cloudstack/api/command/admin/vm/ImportUnmanagedInstanceCmd.java
+++ b/api/src/main/java/org/apache/cloudstack/api/command/admin/vm/ImportUnmanagedInstanceCmd.java
@@ -75,8 +75,8 @@ public class ImportUnmanagedInstanceCmd extends BaseAsyncCmd {
     @Parameter(name = ApiConstants.CLUSTER_ID,
             type = CommandType.UUID,
             entityType = ClusterResponse.class,
-            required = true,
-            description = "The cluster ID")
+            description = "The cluster ID. Required when importing an unmanaged Instance or importing from VMware. " +
+                    "Not used when importing a KVM Instance from an external host, local storage or shared storage")
     private Long clusterId;
 
     @Parameter(name = ApiConstants.NAME,
diff --git a/server/src/main/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImpl.java b/server/src/main/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImpl.java
index 585f00d80eb3..96ac43103a4d 100644
--- a/server/src/main/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImpl.java
+++ b/server/src/main/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImpl.java
@@ -1262,7 +1262,7 @@ protected Cluster basicAccessChecks(Long clusterId) {
             throw new PermissionDeniedException(String.format("Cannot perform this operation, caller account [%s] is not ROOT Admin.", caller.getUuid()));
         }
         if (clusterId == null) {
-            throw new InvalidParameterValueException("Cluster ID cannot be null.");
+            throw new InvalidParameterValueException(String.format("Cluster ID cannot be null, please specify the [%s] parameter.", ApiConstants.CLUSTER_ID));
         }
         final Cluster cluster = clusterDao.findById(clusterId);
         if (cluster == null) {
diff --git a/server/src/test/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImplTest.java b/server/src/test/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImplTest.java
index 30bc769d5d4f..c4225056e003 100644
--- a/server/src/test/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImplTest.java
+++ b/server/src/test/java/org/apache/cloudstack/vm/UnmanagedVMsManagerImplTest.java
@@ -1051,6 +1051,24 @@ private void importFromDisk(String source, Storage.StoragePoolType poolType, Str
         verify(deploymentPlanningManager).planDeployment(any(), planCaptor.capture(), any(), any());
         Assert.assertEquals(poolPodId, planCaptor.getValue().getPodId());
         Assert.assertEquals(poolClusterId, planCaptor.getValue().getClusterId());
+        // the clusterid parameter is not used, the cluster is derived from the storage pool
+        Mockito.verify(cmd, Mockito.never()).getClusterId();
+    }
+
+    @Test(expected = InvalidParameterValueException.class)
+    public void testImportVmFromVmwareMissingClusterId() {
+        ImportVmCmd cmd = Mockito.mock(ImportVmCmd.class);
+        when(cmd.getName()).thenReturn("testVm");
+        when(cmd.getImportSource()).thenReturn("vmware");
+        unmanagedVMsManager.importVm(cmd);
+    }
+
+    @Test(expected = InvalidParameterValueException.class)
+    public void testImportVmFromUnmanagedMissingClusterId() {
+        ImportVmCmd cmd = Mockito.mock(ImportVmCmd.class);
+        when(cmd.getName()).thenReturn("testVm");
+        when(cmd.getImportSource()).thenReturn("unmanaged");
+        unmanagedVMsManager.importVm(cmd);
     }
 
     @Test