diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 088d590..193bfa1 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -38,7 +38,7 @@
   <PropertyGroup Label="Version numbers">
     <!-- MAJOR, MINOR, and PATCH are defined according to SemVer 2.0.0. -->
     <NtsMajorVersion>2</NtsMajorVersion>
-    <NtsMinorVersion>0</NtsMinorVersion>
+    <NtsMinorVersion>1</NtsMinorVersion>
     <NtsPatchVersion>0</NtsPatchVersion>
 
     <NtsBuildTimestamp>$([System.DateTime]::UtcNow.Ticks)</NtsBuildTimestamp>
diff --git a/src/ProjNet/IO/CoordinateSystems/CoordinateSystemWktReader.cs b/src/ProjNet/IO/CoordinateSystems/CoordinateSystemWktReader.cs
index 340dcbf..7cda4f9 100644
--- a/src/ProjNet/IO/CoordinateSystems/CoordinateSystemWktReader.cs
+++ b/src/ProjNet/IO/CoordinateSystems/CoordinateSystemWktReader.cs
@@ -96,7 +96,7 @@ public static IInfo Parse(string wkt)
         /// <returns>An object that implements the IUnit interface.</returns>
         private static IUnit ReadUnit(WktStreamTokenizer tokenizer)
         {
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string unitName = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
@@ -107,8 +107,11 @@ private static IUnit ReadUnit(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",")
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             }
+            else 
+                tokenizer.CheckCloser(bracket);
+
             return new Unit(unitsPerUnit, unitName, authority, authorityCode, string.Empty, string.Empty, string.Empty);
         }
         /// <summary>
@@ -118,7 +121,8 @@ private static IUnit ReadUnit(WktStreamTokenizer tokenizer)
         /// <returns>An object that implements the IUnit interface.</returns>
         private static LinearUnit ReadLinearUnit(WktStreamTokenizer tokenizer)
         {
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
+
             string unitName = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
@@ -129,8 +133,11 @@ private static LinearUnit ReadLinearUnit(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",")
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             }
+            else
+                tokenizer.CheckCloser(bracket);
+
             return new LinearUnit(unitsPerUnit, unitName, authority, authorityCode, string.Empty, string.Empty, string.Empty);
         }
         /// <summary>
@@ -140,7 +147,8 @@ private static LinearUnit ReadLinearUnit(WktStreamTokenizer tokenizer)
         /// <returns>An object that implements the IUnit interface.</returns>
         private static AngularUnit ReadAngularUnit(WktStreamTokenizer tokenizer)
         {
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
+
             string unitName = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
@@ -151,7 +159,11 @@ private static AngularUnit ReadAngularUnit(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",")
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
+            }
+            else
+            {
+                tokenizer.CheckCloser(bracket);
             }
             return new AngularUnit(unitsPerUnit, unitName, authority, authorityCode, string.Empty, string.Empty, string.Empty);
         }
@@ -165,12 +177,12 @@ private static AxisInfo ReadAxis(WktStreamTokenizer tokenizer)
         {
             if (tokenizer.GetStringValue() != "AXIS")
                 tokenizer.ReadToken("AXIS");
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string axisName = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
             string unitname = tokenizer.GetStringValue();
-            tokenizer.ReadToken("]");
+            tokenizer.ReadCloser(bracket);
             switch (unitname.ToUpperInvariant())
             {
                 case "DOWN": return new AxisInfo(axisName, AxisOrientationEnum.Down);
@@ -210,7 +222,7 @@ private static CoordinateSystem ReadCoordinateSystem(string coordinateSystem, Wk
         private static Wgs84ConversionInfo ReadWGS84ConversionInfo(WktStreamTokenizer tokenizer)
         {
             //TOWGS84[0,0,0,0,0,0,0]
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             var info = new Wgs84ConversionInfo();
             tokenizer.NextToken();
             info.Dx = tokenizer.GetNumericValue();
@@ -244,14 +256,14 @@ private static Wgs84ConversionInfo ReadWGS84ConversionInfo(WktStreamTokenizer to
                 }
             }
             if (tokenizer.GetStringValue() != "]")
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             return info;
         }
 
         private static Ellipsoid ReadEllipsoid(WktStreamTokenizer tokenizer)
         {
             //SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]]
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
@@ -265,7 +277,7 @@ private static Ellipsoid ReadEllipsoid(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",") //Read authority
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             }
             var ellipsoid = new Ellipsoid(majorAxis, 0.0, e, true, LinearUnit.Metre, name, authority, authorityCode, string.Empty, string.Empty, string.Empty);
             return ellipsoid;
@@ -275,7 +287,7 @@ private static IProjection ReadProjection(WktStreamTokenizer tokenizer)
         {
             if (tokenizer.GetStringValue() != "PROJECTION")
                 tokenizer.ReadToken("PROJECTION");
-            tokenizer.ReadToken("[");//[
+            var bracket = tokenizer.ReadOpener();
             string projectionName = tokenizer.ReadDoubleQuotedWord();
             string authority = string.Empty;
             long authorityCode = -1L;
@@ -284,20 +296,22 @@ private static IProjection ReadProjection(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",")
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             }
+            else
+                tokenizer.CheckCloser(bracket);
 
             tokenizer.ReadToken(",");//,
             tokenizer.ReadToken("PARAMETER");
             var paramList = new List<ProjectionParameter>();
             while (tokenizer.GetStringValue() == "PARAMETER")
             {
-                tokenizer.ReadToken("[");
+                bracket = tokenizer.ReadOpener();
                 string paramName = tokenizer.ReadDoubleQuotedWord();
                 tokenizer.ReadToken(",");
                 tokenizer.NextToken();
                 double paramValue = tokenizer.GetNumericValue();
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
                 paramList.Add(new ProjectionParameter(paramName, paramValue));
                 //tokenizer.ReadToken(",");
                 //tokenizer.NextToken();
@@ -338,7 +352,7 @@ private static ProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStream
                 AUTHORITY["EPSG","27700"]
             ]
             */
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.ReadToken("GEOGCS");
@@ -356,7 +370,10 @@ private static ProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStream
                 switch (tokenizer.GetStringValue())
                 {
                     case ",":
+                        break;
                     case "]":
+                    case ")":
+                        tokenizer.CheckCloser(bracket);
                         break;
                     case "PROJECTION":
                         projection = ReadProjection(tokenizer);
@@ -372,7 +389,7 @@ private static ProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStream
                         break;
                     case "AUTHORITY":
                         tokenizer.ReadAuthority(out authority, out authorityCode);
-                        //tokenizer.ReadToken("]");
+                        //tokenizer.ReadCloser(bracket);
                         break;
                 }
                 ct = tokenizer.NextToken();
@@ -394,7 +411,7 @@ private static GeocentricCoordinateSystem ReadGeocentricCoordinateSystem(WktStre
              * GEOCCS["<name>", <datum>, <prime meridian>, <linear unit> {,<axis>, <axis>, <axis>} {,<authority>}]
              */
 
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.ReadToken("DATUM");
@@ -424,7 +441,7 @@ private static GeocentricCoordinateSystem ReadGeocentricCoordinateSystem(WktStre
                 if (tokenizer.GetStringValue() == "AUTHORITY")
                 {
                     tokenizer.ReadAuthority(out authority, out authorityCode);
-                    tokenizer.ReadToken("]");
+                    tokenizer.ReadCloser(bracket);
                 }
             }
 
@@ -451,7 +468,7 @@ private static GeographicCoordinateSystem ReadGeographicCoordinateSystem(WktStre
             AUTHORITY["EPSG","4277"]
             ]
             */
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.ReadToken("DATUM");
@@ -480,7 +497,7 @@ private static GeographicCoordinateSystem ReadGeographicCoordinateSystem(WktStre
                 if (tokenizer.GetStringValue() == "AUTHORITY")
                 {
                     tokenizer.ReadAuthority(out authority, out authorityCode);
-                    tokenizer.ReadToken("]");
+                    tokenizer.ReadCloser(bracket);
                 }
             }
 
@@ -502,7 +519,7 @@ private static HorizontalDatum ReadHorizontalDatum(WktStreamTokenizer tokenizer)
             string authority = string.Empty;
             long authorityCode = -1;
 
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.ReadToken("SPHEROID");
@@ -519,7 +536,7 @@ private static HorizontalDatum ReadHorizontalDatum(WktStreamTokenizer tokenizer)
                 else if (tokenizer.GetStringValue() == "AUTHORITY")
                 {
                     tokenizer.ReadAuthority(out authority, out authorityCode);
-                    tokenizer.ReadToken("]");
+                    tokenizer.ReadCloser(bracket);
                 }
             }
             // make an assumption about the datum type.
@@ -531,7 +548,7 @@ private static HorizontalDatum ReadHorizontalDatum(WktStreamTokenizer tokenizer)
         private static PrimeMeridian ReadPrimeMeridian(WktStreamTokenizer tokenizer)
         {
             //PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]
-            tokenizer.ReadToken("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord();
             tokenizer.ReadToken(",");
             tokenizer.NextToken();
@@ -543,8 +560,11 @@ private static PrimeMeridian ReadPrimeMeridian(WktStreamTokenizer tokenizer)
             if (tokenizer.GetStringValue() == ",")
             {
                 tokenizer.ReadAuthority(out authority, out authorityCode);
-                tokenizer.ReadToken("]");
+                tokenizer.ReadCloser(bracket);
             }
+            else
+                tokenizer.CheckCloser(bracket);
+
             // make an assumption about the Angular units - degrees.
             var primeMeridian = new PrimeMeridian(longitude, AngularUnit.Degrees, name, authority, authorityCode, string.Empty, string.Empty, string.Empty);
 
@@ -572,7 +592,7 @@ private static FittedCoordinateSystem ReadFittedCoordinateSystem (WktStreamToken
                  AUTHORITY["CUSTOM","12345"]
              ]
             */
-            tokenizer.ReadToken ("[");
+            var bracket = tokenizer.ReadOpener();
             string name = tokenizer.ReadDoubleQuotedWord ();
             tokenizer.ReadToken (",");
             tokenizer.ReadToken ("PARAM_MT");
@@ -590,11 +610,15 @@ private static FittedCoordinateSystem ReadFittedCoordinateSystem (WktStreamToken
                 switch (tokenizer.GetStringValue ())
                 {
                     case ",":
+                        break;
                     case "]":
+                    case ")":
+                        tokenizer.CheckCloser(bracket);
+
                         break;
                     case "AUTHORITY":
                         tokenizer.ReadAuthority (out authority, out authorityCode);
-                        //tokenizer.ReadToken("]");
+                        //tokenizer.ReadCloser(bracket);
                         break;
                 }
                 ct = tokenizer.NextToken ();
diff --git a/src/ProjNet/IO/CoordinateSystems/WKTStreamTokenizer.cs b/src/ProjNet/IO/CoordinateSystems/WKTStreamTokenizer.cs
index 0c9ec49..c6fa98b 100644
--- a/src/ProjNet/IO/CoordinateSystems/WKTStreamTokenizer.cs
+++ b/src/ProjNet/IO/CoordinateSystems/WKTStreamTokenizer.cs
@@ -91,6 +91,64 @@ public string ReadDoubleQuotedWord()
             return word;
         }
 
+        /// <summary>
+        /// Reads an opener
+        /// </summary>
+        /// <param name="expectedBracket">The expected bracket type.</param>
+        /// <returns>The bracket type encountered</returns>
+        public WktBracket ReadOpener(WktBracket expectedBracket = WktBracket.DontCare)
+        {
+            NextToken();
+            string stringValue = GetStringValue();
+            if (stringValue == "[")
+            {
+                if (expectedBracket == WktBracket.Square || expectedBracket == WktBracket.DontCare)
+                    return WktBracket.Square;
+            }
+            else if (stringValue == "(")
+            {
+                if (expectedBracket == WktBracket.Round || expectedBracket == WktBracket.DontCare)
+                    return WktBracket.Round;
+            }
+
+            string expectedToken = expectedBracket == WktBracket.Square ? "[" : "(";
+            string s = string.Format(_nfi, "Expecting ('{3}') but got a '{0}' at line {1} column {2}.", stringValue, LineNumber, Column, expectedToken);
+            throw new ArgumentException(s);
+        }
+
+        /// <summary>
+        /// Reads an closer
+        /// </summary>
+        /// <param name="expectedBracket">The expected bracket type.</param>
+        public void ReadCloser(WktBracket expectedBracket)
+        {
+            NextToken();
+            CheckCloser(expectedBracket);
+        }
+
+        /// <summary>
+        /// Checks if the current token is a closer of expected type.
+        /// </summary>
+        /// <param name="expectedBracket">The expected bracket type.</param>
+        public void CheckCloser(WktBracket expectedBracket)
+        {
+            string stringValue = GetStringValue();
+            if (stringValue == "]")
+            {
+                if (expectedBracket == WktBracket.Square || expectedBracket == WktBracket.DontCare)
+                    return;
+            }
+            else if (stringValue == ")")
+            {
+                if (expectedBracket == WktBracket.Round || expectedBracket == WktBracket.DontCare)
+                    return;
+            }
+
+            string expectedToken = expectedBracket == WktBracket.Square ? "]" : ")";
+            string s = string.Format(_nfi, "Expecting ('{3}') but got a '{0}' at line {1} column {2}.", stringValue, LineNumber, Column, expectedToken);
+            throw new ArgumentException(s);
+        }
+
         /// <summary>
         /// Reads the authority and authority code.
         /// </summary>
@@ -101,7 +159,7 @@ public void ReadAuthority(out string authority, out long authorityCode)
             //AUTHORITY["EPGS","9102"]]
             if (GetStringValue() != "AUTHORITY")
                 ReadToken("AUTHORITY");
-            ReadToken("[");
+            var bracket = ReadOpener();
             authority = ReadDoubleQuotedWord();
             ReadToken(",");
             NextToken();
@@ -109,7 +167,7 @@ public void ReadAuthority(out string authority, out long authorityCode)
                 authorityCode = (long) GetNumericValue();
             else
                 long.TryParse(ReadDoubleQuotedWord(), NumberStyles.Any, _nfi, out authorityCode);
-            ReadToken("]");
+            ReadCloser(bracket);
         }
     }
 }
diff --git a/src/ProjNet/IO/CoordinateSystems/WktBracket.cs b/src/ProjNet/IO/CoordinateSystems/WktBracket.cs
new file mode 100644
index 0000000..6cef3ac
--- /dev/null
+++ b/src/ProjNet/IO/CoordinateSystems/WktBracket.cs
@@ -0,0 +1,39 @@
+// Copyright 2021 - NetTopologySuite - Team
+//
+// This file is part of ProjNet.
+// ProjNet is free software; you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+// 
+// ProjNet is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+
+// You should have received a copy of the GNU Lesser General Public License
+// along with ProjNet; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+namespace ProjNet.IO.CoordinateSystems
+{
+    /// <summary>
+    /// An enumeration of possible bracket types
+    /// </summary>
+    internal enum WktBracket
+    {
+        /// <summary>
+        /// Bracket type not specified.
+        /// </summary>
+        DontCare,
+        /// <summary>
+        /// Opener &quot;<c>(</c>&quot;, closer &quot;<c>)</c>&quot;
+        /// </summary>
+        Round,
+        /// <summary>
+        /// Opener &quot;<c>[</c>&quot;, closer &quot;<c>]</c>&quot;
+        /// </summary>
+        Square,
+        //Brace
+    }
+}
diff --git a/src/ProjNet/ProjNET.csproj b/src/ProjNet/ProjNET.csproj
index 2c3fc9a..e3d1e27 100644
--- a/src/ProjNet/ProjNET.csproj
+++ b/src/ProjNet/ProjNET.csproj
@@ -5,6 +5,7 @@
     <RootNamespace>ProjNet</RootNamespace>
     <TargetFramework>netstandard2.0</TargetFramework>
     <SignAssembly>true</SignAssembly>
+    <EnableApiCompat>true</EnableApiCompat>
   </PropertyGroup>
 
   <PropertyGroup Label="Assembly Info">
@@ -28,4 +29,11 @@ Proj.NET performs point-to-point coordinate conversions between geodetic coordin
     <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" />
   </ItemGroup>
 
+	<ItemGroup Condition=" '$(EnableApiCompat)' == 'true' ">
+		<PackageReference Include="Microsoft.DotNet.ApiCompat" Version="6.0.0-beta.21159.11" PrivateAssets="All" />
+		<PackageDownload Include="ProjNet" Version="[2.0.0]" PrivateAssets="All" />
+
+		<ResolvedMatchingContract Include="$(NugetPackageRoot)projnet\2.0.0\lib\netstandard2.0\ProjNet.dll" />
+	</ItemGroup>
+
 </Project>
diff --git a/test/ProjNet.Tests/WKT/WKTCoordSysParserTests.cs b/test/ProjNet.Tests/WKT/WKTCoordSysParserTests.cs
index 97bc3cb..8c17209 100644
--- a/test/ProjNet.Tests/WKT/WKTCoordSysParserTests.cs
+++ b/test/ProjNet.Tests/WKT/WKTCoordSysParserTests.cs
@@ -84,6 +84,10 @@ public void TestProjectedCoordinateSystem_EPSG_2918()
             ProjectedCoordinateSystem pcs = null;
             Assert.That(() => pcs = _coordinateSystemFactory.CreateFromWkt(wkt) as ProjectedCoordinateSystem, Throws.Nothing);
 
+            ProjectedCoordinateSystem pcs2 = null;
+            Assert.That(() => pcs2 = _coordinateSystemFactory.CreateFromWkt(wkt.Replace("[", "(").Replace("]", ")")) as ProjectedCoordinateSystem, Throws.Nothing);
+            Assert.That(pcs.EqualParams(pcs2), Is.True);
+
             Assert.That(pcs, Is.Not.Null, "Could not parse WKT: " + wkt);
             CheckInfo(pcs, "NAD83(HARN) / Texas Central (ftUS)", "EPSG", 2918);
 
@@ -118,8 +122,10 @@ public void ParseAllWKTs()
             int parseCount = 0;
             foreach (var wkt in SRIDReader.GetSrids())
             {
-                var cs = _coordinateSystemFactory.CreateFromWkt(wkt.Wkt);
-                Assert.IsNotNull(cs, "Could not parse WKT: " + wkt);
+                var cs1 = _coordinateSystemFactory.CreateFromWkt(wkt.Wkt);
+                Assert.IsNotNull(cs1, "Could not parse WKT: " + wkt);
+                var cs2 = _coordinateSystemFactory.CreateFromWkt(wkt.Wkt.Replace("[", "(").Replace("]", ")"));
+                Assert.That(cs1.EqualParams(cs2), Is.True);
                 parseCount++;
             }
             Assert.That(parseCount, Is.GreaterThan(2671), "Not all WKT was parsed");
@@ -245,9 +251,13 @@ public void TestProjectedCoordinateSystem_EPSG27700_UnitBeforeProjection()
                  "AXIS[\"Northing\",NORTH]]";
 
             ProjectedCoordinateSystem pcs = null;
-
             Assert.That(() => pcs = _coordinateSystemFactory.CreateFromWkt(wkt) as ProjectedCoordinateSystem, Throws.Nothing);
 
+            ProjectedCoordinateSystem pcs2 = null;
+            Assert.That(() => pcs2 = _coordinateSystemFactory.CreateFromWkt(wkt.Replace("[", "(").Replace("]", ")")) as ProjectedCoordinateSystem, Throws.Nothing);
+            Assert.That(pcs.EqualParams(pcs2), Is.True);
+
+
             CheckInfo(pcs, "OSGB 1936 / British National Grid", "EPSG", 27700);
 
             var gcs = pcs.GeographicCoordinateSystem;