diff --git a/src/NzbDrone.Core.Test/ParserTests/FingerprintingServiceFixture.cs b/src/NzbDrone.Core.Test/ParserTests/FingerprintingServiceFixture.cs
index cda3b4a8f..e004d6a1a 100644
--- a/src/NzbDrone.Core.Test/ParserTests/FingerprintingServiceFixture.cs
+++ b/src/NzbDrone.Core.Test/ParserTests/FingerprintingServiceFixture.cs
@@ -7,6 +7,11 @@ using System.IO;
 using System.Linq;
 using NzbDrone.Core.Parser.Model;
 using System;
+using NzbDrone.Common.Http;
+using Moq;
+using static NzbDrone.Core.Parser.FingerprintingService;
+using NzbDrone.Test.Common;
+using System.Net;
 
 namespace NzbDrone.Core.Test.ParserTests
 {
@@ -181,5 +186,19 @@ FINGERPRINT=AQAHJlMURlEURcgP6cwRD43Y4Ptw9FowncWPWkf6GB9-JYdP9OgJHw8u4Apw4SsOHMdx
             idpairs[1].Item1.AcoustIdResults.Should().Contain("30f3f33e-8d0c-4e69-8539-cbd701d18f28");
             idpairs[2].Item1.AcoustIdResults.Should().BeNull();
         }
+
+        [Test]
+        public void should_not_throw_if_api_returns_html()
+        {
+            Mocker.GetMock<IHttpClient>().Setup(x => x.Post<LookupResponse>(It.IsAny<HttpRequest>()))
+                                         .Callback<HttpRequest>(req => throw new UnexpectedHtmlContentException(new HttpResponse(req, req.Headers, "html content", HttpStatusCode.Accepted)));
+
+            var path = Path.Combine(TestContext.CurrentContext.TestDirectory, "Files", "Media", "nin.mp3");
+            var localTrack = new LocalTrack { Path = path };
+            Subject.Lookup(new List<LocalTrack> { localTrack }, 0.5);
+            localTrack.AcoustIdResults.Should().BeNull();
+
+            ExceptionVerification.ExpectedWarns(1);
+        }
     }
 }
diff --git a/src/NzbDrone.Core/Parser/FingerprintingService.cs b/src/NzbDrone.Core/Parser/FingerprintingService.cs
index ee8a041aa..150051336 100644
--- a/src/NzbDrone.Core/Parser/FingerprintingService.cs
+++ b/src/NzbDrone.Core/Parser/FingerprintingService.cs
@@ -360,7 +360,18 @@ namespace NzbDrone.Core.Parser
             httpRequest.Headers.ContentType = "application/x-www-form-urlencoded";
             httpRequest.SuppressHttpError = true;
 
-            var httpResponse = _httpClient.Post<LookupResponse>(httpRequest);
+            HttpResponse<LookupResponse> httpResponse;
+
+            try
+            {
+                httpResponse = _httpClient.Post<LookupResponse>(httpRequest);
+            }
+            catch (UnexpectedHtmlContentException e)
+            {
+                _logger.Warn(e, "AcoustId API gave invalid response");
+                return;
+            }
+
             var response = httpResponse.Resource;
 
             // The API will give errors if fingerprint isn't found or is invalid.
@@ -407,33 +418,33 @@ namespace NzbDrone.Core.Parser
             _logger.Debug($"*** FingerprintingService TestCaseGenerator ***\n{JsonConvert.SerializeObject(output, SerializerSettings)}");
         }
 
-        private class LookupResponse
+        public class LookupResponse
         {
             public string Status { get; set; }
             public LookupError Error { get; set; }
             public List<LookupResultListItem> Fingerprints { get; set; }
         }
 
-        private class LookupError
+        public class LookupError
         {
             public string Message { get; set; }
             public int Code { get; set; }
         }
 
-        private class LookupResultListItem
+        public class LookupResultListItem
         {
             public int index { get; set; }
             public List<LookupResult> Results { get; set; }
         }
 
-        private class LookupResult
+        public class LookupResult
         {
             public string Id { get; set; }
             public double Score { get; set; }
             public List<RecordingResult> Recordings { get; set; }
         }
 
-        private class RecordingResult
+        public class RecordingResult
         {
             public string Id { get; set; }
         }