diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/PackageBuilder.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/PackageBuilder.cs
index d273d47e056..e433838a3ec 100644
--- a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/PackageBuilder.cs
+++ b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/PackageBuilder.cs
@@ -780,7 +780,11 @@ private HashSet<string> WriteFiles(ZipArchive package, HashSet<string> filesWith
                         }
                         else
                         {
+#if NETCOREAPP
+                            filesWithoutExtensions.Add($"/{file.Path.Replace("\\", "/", StringComparison.Ordinal)}");
+#else
                             filesWithoutExtensions.Add($"/{file.Path.Replace("\\", "/")}");
+#endif
                         }
                     }
                     catch
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageExtraction/ZipArchiveExtensions.cs b/src/NuGet.Core/NuGet.Packaging/PackageExtraction/ZipArchiveExtensions.cs
index 2f1ef3728d3..1d5fbf17744 100644
--- a/src/NuGet.Core/NuGet.Packaging/PackageExtraction/ZipArchiveExtensions.cs
+++ b/src/NuGet.Core/NuGet.Packaging/PackageExtraction/ZipArchiveExtensions.cs
@@ -35,7 +35,11 @@ public static IEnumerable<string> GetFiles(this ZipArchive zipArchive)
         private static string UnescapePath(string path)
         {
             if (path != null
+#if NETCOREAPP
+                && path.IndexOf('%', StringComparison.Ordinal) > -1)
+#else
                 && path.IndexOf('%') > -1)
+#endif
             {
                 return Uri.UnescapeDataString(path);
             }
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageFolderReader.cs b/src/NuGet.Core/NuGet.Packaging/PackageFolderReader.cs
index 13fbec03a28..5a71341dffe 100644
--- a/src/NuGet.Core/NuGet.Packaging/PackageFolderReader.cs
+++ b/src/NuGet.Core/NuGet.Packaging/PackageFolderReader.cs
@@ -150,7 +150,11 @@ public override IEnumerable<string> GetFiles(string folder)
         /// </summary>
         private static bool IsFileInRoot(string path)
         {
+#if NETCOREAPP
+            return path.IndexOf('/', StringComparison.Ordinal) == -1;
+#else
             return path.IndexOf('/') == -1;
+#endif
         }
 
         /// <summary>
diff --git a/src/NuGet.Core/NuGet.Packaging/Rules/UpholdBuildConventionRule.cs b/src/NuGet.Core/NuGet.Packaging/Rules/UpholdBuildConventionRule.cs
index 936796b6118..29dcd6b530f 100644
--- a/src/NuGet.Core/NuGet.Packaging/Rules/UpholdBuildConventionRule.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Rules/UpholdBuildConventionRule.cs
@@ -103,7 +103,11 @@ internal class ConventionViolator
 
             public ConventionViolator(string filePath, string extension, string expectedFile)
             {
+#if NETCOREAPP
+                Path = filePath.Replace(filePath.Split('/')[filePath.Count(p => p == '/')], string.Empty, StringComparison.OrdinalIgnoreCase);
+#else
                 Path = filePath.Replace(filePath.Split('/')[filePath.Count(p => p == '/')], string.Empty);
+#endif
                 Extension = extension;
                 ExpectedPath = expectedFile;
             }
diff --git a/src/NuGet.Core/NuGet.Packaging/Signing/Archive/EndOfCentralDirectoryRecord.cs b/src/NuGet.Core/NuGet.Packaging/Signing/Archive/EndOfCentralDirectoryRecord.cs
index f754422a39e..5757e81c8c6 100644
--- a/src/NuGet.Core/NuGet.Packaging/Signing/Archive/EndOfCentralDirectoryRecord.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Signing/Archive/EndOfCentralDirectoryRecord.cs
@@ -106,7 +106,11 @@ private static void ThrowByteSignatureNotFoundException(byte[] signature)
             throw new InvalidDataException(
                 string.Format(CultureInfo.CurrentCulture,
                 Strings.ErrorByteSignatureNotFound,
+#if NETCOREAPP
+                BitConverter.ToString(signature).Replace("-", "", StringComparison.Ordinal)));
+#else
                 BitConverter.ToString(signature).Replace("-", "")));
+#endif
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NuGet.Core/NuGet.Packaging/Signing/Content/KeyPairFileReader.cs b/src/NuGet.Core/NuGet.Packaging/Signing/Content/KeyPairFileReader.cs
index 468fb14e466..f7aa36e0eb5 100644
--- a/src/NuGet.Core/NuGet.Packaging/Signing/Content/KeyPairFileReader.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Signing/Content/KeyPairFileReader.cs
@@ -73,7 +73,11 @@ public Dictionary<string, string> ReadSection()
 
         private static KeyValuePair<string, string> GetProperty(string line)
         {
+#if NETCOREAPP
+            var pos = line.IndexOf(':', StringComparison.Ordinal);
+#else
             var pos = line.IndexOf(':');
+#endif
 
             if (pos > 0)
             {
diff --git a/src/NuGet.Core/NuGet.Packaging/Signing/DerEncoding/DerGeneralizedTime.cs b/src/NuGet.Core/NuGet.Packaging/Signing/DerEncoding/DerGeneralizedTime.cs
index 20703ea3446..a6eaf5c45e4 100644
--- a/src/NuGet.Core/NuGet.Packaging/Signing/DerEncoding/DerGeneralizedTime.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Signing/DerEncoding/DerGeneralizedTime.cs
@@ -32,7 +32,11 @@ public static DerGeneralizedTime Read(string decodedTime)
                 throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
             }
 
+#if NETCOREAPP
+            var decimalIndex = decodedTime.IndexOf('.', StringComparison.Ordinal);
+#else
             var decimalIndex = decodedTime.IndexOf('.');
+#endif
             var stringToParse = decodedTime;
             string format;
 
@@ -88,4 +92,4 @@ public static DerGeneralizedTime Read(string decodedTime)
             throw new CryptographicException(SR.Cryptography_Der_Invalid_Encoding);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/NuGet.Core/NuGet.Packaging/Signing/Timestamp/Rfc3161TimestampVerificationUtility.cs b/src/NuGet.Core/NuGet.Packaging/Signing/Timestamp/Rfc3161TimestampVerificationUtility.cs
index 46a63c47775..1f6e2da5dbb 100644
--- a/src/NuGet.Core/NuGet.Packaging/Signing/Timestamp/Rfc3161TimestampVerificationUtility.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Signing/Timestamp/Rfc3161TimestampVerificationUtility.cs
@@ -37,7 +37,7 @@ internal static bool TryReadTSTInfoFromSignedCms(
             out IRfc3161TimestampTokenInfo tstInfo)
         {
             tstInfo = null;
-            if (timestampCms.ContentInfo.ContentType.Value.Equals(Oids.TSTInfoContentType))
+            if (timestampCms.ContentInfo.ContentType.Value.Equals(Oids.TSTInfoContentType, StringComparison.Ordinal))
             {
                 tstInfo = Rfc3161TimestampTokenInfoFactory.Create(timestampCms.ContentInfo.Content);
                 return true;
diff --git a/src/NuGet.Core/NuGet.Packaging/Signing/Utility/CertificateUtility.cs b/src/NuGet.Core/NuGet.Packaging/Signing/Utility/CertificateUtility.cs
index cdf43204c58..36eeaf32269 100644
--- a/src/NuGet.Core/NuGet.Packaging/Signing/Utility/CertificateUtility.cs
+++ b/src/NuGet.Core/NuGet.Packaging/Signing/Utility/CertificateUtility.cs
@@ -263,7 +263,11 @@ public static string GetHashString(X509Certificate2 certificate, HashAlgorithmNa
             }
 
             var certificateFingerprint = GetHash(certificate, hashAlgorithm);
+#if NETCOREAPP
+            return BitConverter.ToString(certificateFingerprint).Replace("-", "", StringComparison.Ordinal);
+#else
             return BitConverter.ToString(certificateFingerprint).Replace("-", "");
+#endif
         }
 
         /// <summary>
@@ -325,7 +329,11 @@ public static bool IsSelfIssued(X509Certificate2 certificate)
                     if (reader.HasTag(keyIdentifierTag))
                     {
                         var keyIdentifier = reader.ReadValue(keyIdentifierTag);
+#if NETCOREAPP
+                        var akiKeyIdentifier = BitConverter.ToString(keyIdentifier).Replace("-", "", StringComparison.Ordinal);
+#else
                         var akiKeyIdentifier = BitConverter.ToString(keyIdentifier).Replace("-", "");
+#endif
 
                         return string.Equals(skiExtension.SubjectKeyIdentifier, akiKeyIdentifier, StringComparison.OrdinalIgnoreCase);
                     }
@@ -347,4 +355,4 @@ public static IReadOnlyList<byte[]> GetRawDataForCollection(X509Certificate2Coll
             return certificatesRawData.AsReadOnly();
         }
     }
-}
\ No newline at end of file
+}