diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9af9b0e..a831ae0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 # Changes in Medidata.MAuth
+## v5.1.7
+- **[Core]** Fix preprocessor for sync methods
+
 ## v5.1.6
 - **[Core]** Fix bug in MAuth verification.
 
diff --git a/src/Medidata.MAuth.Core/HttpRequestMessageExtensions.cs b/src/Medidata.MAuth.Core/HttpRequestMessageExtensions.cs
index 2be15ef..32f5482 100644
--- a/src/Medidata.MAuth.Core/HttpRequestMessageExtensions.cs
+++ b/src/Medidata.MAuth.Core/HttpRequestMessageExtensions.cs
@@ -14,7 +14,7 @@ public async static Task<byte[]> GetRequestContentAsBytesAsync(this HttpRequestM
                     : await request.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
         }
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         public static byte[] GetRequestContentAsBytes(this HttpRequestMessage request)
         {
             using var memoryStream = new MemoryStream();
diff --git a/src/Medidata.MAuth.Core/IMAuthCore.cs b/src/Medidata.MAuth.Core/IMAuthCore.cs
index cd5560c..005ca2e 100644
--- a/src/Medidata.MAuth.Core/IMAuthCore.cs
+++ b/src/Medidata.MAuth.Core/IMAuthCore.cs
@@ -13,7 +13,7 @@ internal interface IMAuthCore
 
         (string mAuthHeaderKey, string mAuthTimeHeaderKey) GetHeaderKeys();
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         HttpRequestMessage SignSync(HttpRequestMessage request, MAuthSigningOptions options);
 #endif
     }
diff --git a/src/Medidata.MAuth.Core/MAuthCore.cs b/src/Medidata.MAuth.Core/MAuthCore.cs
index 4df6b6c..18b5b54 100644
--- a/src/Medidata.MAuth.Core/MAuthCore.cs
+++ b/src/Medidata.MAuth.Core/MAuthCore.cs
@@ -153,7 +153,7 @@ internal string CalculatePayload(HttpRequestMessage request, PrivateKeyAuthentic
             return (Constants.MAuthHeaderKey, Constants.MAuthTimeHeaderKey);
         }
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         public HttpRequestMessage SignSync(HttpRequestMessage request, MAuthSigningOptions options)
         {
             var authInfo = new PrivateKeyAuthenticationInfo()
diff --git a/src/Medidata.MAuth.Core/MAuthCoreV2.cs b/src/Medidata.MAuth.Core/MAuthCoreV2.cs
index bf6d62c..2f19a79 100644
--- a/src/Medidata.MAuth.Core/MAuthCoreV2.cs
+++ b/src/Medidata.MAuth.Core/MAuthCoreV2.cs
@@ -165,7 +165,7 @@ internal string CalculatePayload(
             return (Constants.MAuthHeaderKeyV2, Constants.MAuthTimeHeaderKeyV2);
         }
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         /// <summary>
         /// Signs an HTTP request with the MAuth-specific authentication information.
         /// </summary>
diff --git a/src/Medidata.MAuth.Core/MAuthSigningHandler.cs b/src/Medidata.MAuth.Core/MAuthSigningHandler.cs
index 8d3a748..d110414 100644
--- a/src/Medidata.MAuth.Core/MAuthSigningHandler.cs
+++ b/src/Medidata.MAuth.Core/MAuthSigningHandler.cs
@@ -68,7 +68,7 @@ protected override async Task<HttpResponseMessage> SendAsync(
                 .ConfigureAwait(continueOnCapturedContext: false);
         }
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         /// <summary>
         /// Signs an HTTP request with the MAuth-specific authentication information and sends the request to the
         /// inner handler to send to the server a synchronous operation.
diff --git a/tests/Medidata.MAuth.CoreTests/MAuthAuthenticatorTests.cs b/tests/Medidata.MAuth.CoreTests/MAuthAuthenticatorTests.cs
index e8914b8..5633f20 100644
--- a/tests/Medidata.MAuth.CoreTests/MAuthAuthenticatorTests.cs
+++ b/tests/Medidata.MAuth.CoreTests/MAuthAuthenticatorTests.cs
@@ -416,7 +416,7 @@ public static async Task AuthenticateRequest_WithMWSV2Request_AfterNumberOfAttem
             Assert.Equal(HttpStatusCode.ServiceUnavailable, innerException.Responses.First().StatusCode);
         }
 
- #if NET5_0
+ #if NET5_0_OR_GREATER
         [Theory]
         [InlineData("GET")]
         [InlineData("DELETE")]
diff --git a/tests/Medidata.MAuth.CoreTests/MAuthSigningHandlerTests.cs b/tests/Medidata.MAuth.CoreTests/MAuthSigningHandlerTests.cs
index e5a8676..f04b083 100644
--- a/tests/Medidata.MAuth.CoreTests/MAuthSigningHandlerTests.cs
+++ b/tests/Medidata.MAuth.CoreTests/MAuthSigningHandlerTests.cs
@@ -94,7 +94,7 @@ public static async Task SendAsync_WithSignVersionsMWSAndMWSV2_WillSignWithBothM
             Assert.Equal(testData.SignedTime, long.Parse(actual.MAuthTimeHeaderV2).FromUnixTimeSeconds());
         }
 
-#if NET5_0
+#if NET5_0_OR_GREATER
         [Theory]
         [InlineData("GET")]
         [InlineData("DELETE")]
diff --git a/version.props b/version.props
index bf48726..ad274b1 100644
--- a/version.props
+++ b/version.props
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
   <PropertyGroup>
-    <Version>5.1.6</Version>
+    <Version>5.1.7</Version>
   </PropertyGroup>
 </Project>