diff --git a/src/Numerics/Numerics.csproj b/src/Numerics/Numerics.csproj
index 1aa53dd2..facde6f5 100644
--- a/src/Numerics/Numerics.csproj
+++ b/src/Numerics/Numerics.csproj
@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFrameworks>net5.0;net461;net48;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>net5.0;netcoreapp2.1;net461;net48;netstandard2.1;netstandard2.0</TargetFrameworks>
     <AssemblyName>MathNet.Numerics</AssemblyName>
     <RootNamespace>MathNet.Numerics</RootNamespace>
     <IsPackable>true</IsPackable>
diff --git a/src/Numerics/Random/RandomSource.cs b/src/Numerics/Random/RandomSource.cs
index 0eec22e1..9e8cddc4 100644
--- a/src/Numerics/Random/RandomSource.cs
+++ b/src/Numerics/Random/RandomSource.cs
@@ -469,8 +469,8 @@ namespace MathNet.Numerics.Random
 
             DoSampleBytes(buffer);
         }
-        
-#if NETCOREAPP2_1_OR_GREATER
+
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
         /// <summary>
         /// Fills the elements of a specified array of bytes with random numbers.
         /// </summary>
@@ -532,7 +532,7 @@ namespace MathNet.Numerics.Random
             }
         }
 
-#if NETCOREAPP2_1_OR_GREATER
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
         /// <summary>
         /// Fills the elements of a specified array of bytes with random numbers in full range, including zero and 255 (<see cref="F:System.Byte.MaxValue"/>).
         /// </summary>