diff --git a/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/src/Listeners/EventHubsTargetScaler.cs b/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/src/Listeners/EventHubsTargetScaler.cs
index b49755406cb9..ecccf912a7ce 100644
--- a/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/src/Listeners/EventHubsTargetScaler.cs
+++ b/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/src/Listeners/EventHubsTargetScaler.cs
@@ -86,7 +86,20 @@ internal static TargetScalerResult ThrottleScaleDownIfNecessaryInternal(TargetSc
         internal TargetScalerResult GetScaleResultInternal(TargetScalerContext context, long eventCount, int partitionCount)
         {
             int desiredConcurrency = GetDesiredConcurrencyInternal(context);
-            int desiredWorkerCount = (int)Math.Ceiling(eventCount / (decimal)desiredConcurrency);
+
+            int desiredWorkerCount;
+            try
+            {
+                checked
+                {
+                    desiredWorkerCount = (int)Math.Ceiling(eventCount / (decimal)desiredConcurrency);
+                }
+            }
+            catch (OverflowException)
+            {
+                desiredWorkerCount = int.MaxValue;
+            }
+
             int[] sortedValidWorkerCounts = GetSortedValidWorkerCountsForPartitionCount(partitionCount);
             int validatedTargetWorkerCount = GetValidWorkerCount(desiredWorkerCount, sortedValidWorkerCounts);
 
diff --git a/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/tests/EventHubsTargetScalerTests.cs b/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/tests/EventHubsTargetScalerTests.cs
index c9018e27afe9..0fcd158e1c8c 100644
--- a/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/tests/EventHubsTargetScalerTests.cs
+++ b/sdk/eventhub/Microsoft.Azure.WebJobs.Extensions.EventHubs/tests/EventHubsTargetScalerTests.cs
@@ -76,16 +76,18 @@ public void ThrottleScaleDownIfNecessaryInternal_ReturnsExpected(int currentTarg
         }
 
         [Test]
-        // Using concurrency of 10.
-        [TestCase(10, 10, 1)]
-        [TestCase(20, 10, 2)]
-        [TestCase(30, 10, 3)]
-        [TestCase(60, 10, 10)]
-        [TestCase(70, 10, 10)]
-        [TestCase(150, 10, 10)]
-        public void GetScaleResultInternal_ReturnsExpected(long eventCount, int partitionCount, int expectedTargetWorkerCount)
+        // Using default concurrency of 10.
+        [TestCase(10, 10, 10, 1)]
+        [TestCase(20, 10, 10, 2)]
+        [TestCase(30, 10, 10, 3)]
+        [TestCase(60, 10, 10, 10)]
+        [TestCase(70, 10, 10, 10)]
+        [TestCase(150, 10, 10, 10)]
+        [TestCase(2147483650, 1, 1, 1)] // Testing eventCount > int.MaxInt is 2147483647
+        [TestCase(21474836500, 1000, 1, 1000)] // Testing eventCount > int.MaxInt is 2147483647, with concurrency 1 to force overflow
+        public void GetScaleResultInternal_ReturnsExpected(long eventCount, int partitionCount, int? concurrency, int expectedTargetWorkerCount)
         {
-            TargetScalerResult result = _targetScaler.GetScaleResultInternal(new TargetScalerContext { InstanceConcurrency = 10 }, eventCount, partitionCount);
+            TargetScalerResult result = _targetScaler.GetScaleResultInternal(new TargetScalerContext { InstanceConcurrency = concurrency }, eventCount, partitionCount);
             Assert.AreEqual(expectedTargetWorkerCount, result.TargetWorkerCount);
         }