diff --git a/src/main/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacher.java b/src/main/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacher.java
index 0e915b71..69ab105b 100644
--- a/src/main/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacher.java
+++ b/src/main/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacher.java
@@ -29,7 +29,10 @@ public DefaultRPADatasetCacher(RPACachingService rpaCachingService) {
     public String cache(String datasetId) throws RequestProcessingException {
         String randomId;
         try {
-            randomId = rpaCachingService.cacheAndGenerateRandomId(datasetId, "");
+            // Replaced "" with null because passing an empty string would break the logic downstream. 
+            // An empty string would match the first version available, while in this scenario, 
+            // when the version is not provided, we want to select the latest version. Passing null achieves this.
+            randomId = rpaCachingService.cacheAndGenerateRandomId(datasetId, null);
         } catch (Exception e) {
             this.logCachingException(e);
             throw new RequestProcessingException(e.getMessage());
diff --git a/src/test/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacherTest.java b/src/test/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacherTest.java
index 3e3ae905..37e4f64f 100644
--- a/src/test/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacherTest.java
+++ b/src/test/java/gov/nist/oar/distrib/service/rpa/DefaultRPADatasetCacherTest.java
@@ -11,6 +11,7 @@
 import org.mockito.junit.MockitoJUnitRunner;
 
 import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.times;
@@ -30,7 +31,7 @@ public void setUp() {
         MockitoAnnotations.initMocks(this);
         rpaDatasetCacher = new DefaultRPADatasetCacher(rpaCachingService);
         datasetId = "mds2-2909";
-        version = "";
+        version = null;
     }
 
     @Test
@@ -65,7 +66,7 @@ public void testCache_invalidDatasetId() throws Exception {
         String invalidDatasetId = "ark:/invalid_id";
 
          // Throw an IllegalArgumentException for the invalid datasetId when the cacheAndGenerateRandomId method is called
-        when(rpaCachingService.cacheAndGenerateRandomId(eq(invalidDatasetId), anyString()))
+        when(rpaCachingService.cacheAndGenerateRandomId(eq(invalidDatasetId), any()))
                 .thenThrow(new IllegalArgumentException("Invalid dataset ID format: " + invalidDatasetId));
 
         rpaDatasetCacher.cache(invalidDatasetId);