diff --git a/.circleci/config.yml b/.circleci/config.yml
index 9f4a69b..5da9191 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -64,7 +64,7 @@ jobs:
 
   smoke_test:
     machine:
-      image: ubuntu-2004:202107-02
+      image: ubuntu-2204:2024.01.1
     steps:
       - checkout
       - attach_workspace:
diff --git a/src/Honeycomb.OpenTelemetry/HoneycombOptions.cs b/src/Honeycomb.OpenTelemetry/HoneycombOptions.cs
index 5585c10..da94ddc 100644
--- a/src/Honeycomb.OpenTelemetry/HoneycombOptions.cs
+++ b/src/Honeycomb.OpenTelemetry/HoneycombOptions.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Metrics;
+using System.Text.RegularExpressions;
 
 namespace Honeycomb.OpenTelemetry
 {
@@ -18,6 +19,8 @@ public class HoneycombOptions
         private const string OtelExporterOtlpProtocolGrpc = "grpc";
         private const string OtelExporterHttpTracesPath = "/v1/traces";
         private const string OtelExporterHttpMetricsPath = "/v1/metrics";
+        private const string ClassicKeyRegex = "^[a-f0-9]*$";
+        private const string IngestClassicKeyRegex = "^hc[a-z]ic_[a-z0-9]*$";
         private bool isHttp = false;
 
         /// <summary>
@@ -48,12 +51,27 @@ public class HoneycombOptions
         public string ApiKey { get; set; }
 
         /// <summary>
-        /// Returns whether the provided API key is a legacy key.
+        /// Returns whether the provided API key is a classic key.
         /// </summary>
         /// <remarks>
-        /// Legacy keys have 32 characters.
+        /// Classic configuration keys have 32 characters and classic ingest keys have 64 characters.
         /// </remarks>
-        internal static bool IsClassicKey(string apikey) => apikey?.Length == 32;
+        internal static bool IsClassicKey(string apikey)
+        {
+            if (String.IsNullOrEmpty(apikey))
+            {
+                return false;
+            }
+            else if (apikey.Length == 32)
+            {
+                return Regex.Match(apikey, ClassicKeyRegex).Success;
+            }
+            else if (apikey.Length == 64)
+            {
+                return Regex.Match(apikey, IngestClassicKeyRegex).Success;
+            }
+            return false;
+        }
 
         /// <summary>
         /// Write links to honeycomb traces as they come in
diff --git a/test/Honeycomb.OpenTelemetry.Tests/HoneycombOptionsTests.cs b/test/Honeycomb.OpenTelemetry.Tests/HoneycombOptionsTests.cs
index 34ed169..03ab181 100644
--- a/test/Honeycomb.OpenTelemetry.Tests/HoneycombOptionsTests.cs
+++ b/test/Honeycomb.OpenTelemetry.Tests/HoneycombOptionsTests.cs
@@ -523,17 +523,17 @@ public void DoesNotAppendMetricsPathToGenericEndpointIfPathSpecified(string prot
             Assert.DoesNotContain("/v1/metrics", options.GetMetricsEndpoint());
         }
 
-        [Fact]
-        public void Legacy_key_length()
-        {
-            var options = new HoneycombOptions { ApiKey = "1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a" };
-            Assert.True(HoneycombOptions.IsClassicKey(options.ApiKey));
-        }
-        [Fact]
-        public void Not_legacy_key_length()
+        [Theory]
+        [InlineData("", false)]
+        [InlineData("12345678901234567890123456789012", true)]
+        [InlineData("hcaic_1234567890123456789012345678901234567890123456789012345678", true)]
+        [InlineData("kgvSpPwegJshQkuowXReLD", false)]
+        [InlineData("hcaic_12345678901234567890123456", false)]
+        [InlineData("hcxik_01hqk4k20cjeh63wca8vva5stw70nft6m5n8wr8f5mjx3762s8269j50wc", false)]
+        public void IsClassicKey(string key, bool expected)
         {
-            var options = new HoneycombOptions { ApiKey = "specialenvkey" };
-            Assert.False(HoneycombOptions.IsClassicKey(options.ApiKey));
+            var options = new HoneycombOptions { ApiKey = key };
+            Assert.Equal(HoneycombOptions.IsClassicKey(key), expected);
         }
     }
-}
\ No newline at end of file
+}