diff --git a/src/Sources/linux.common/socket.cs b/src/Sources/linux.common/socket.cs
index fa5b7d9..b72dfbc 100644
--- a/src/Sources/linux.common/socket.cs
+++ b/src/Sources/linux.common/socket.cs
@@ -237,7 +237,7 @@ public static unsafe partial class LibC
         public static int SOL_KCM => 281;
         public static int SOL_TLS => 282;
 
-        public static int SOMAXCONN => 128;
+        public static int SOMAXCONN => 4096;
 
         public static int MSG_OOB => 1;
         public static int MSG_PEEK => 2;
diff --git a/test/Tmds.LibC.Tests/ConstantsTests.cs b/test/Tmds.LibC.Tests/ConstantsTests.cs
index 8a0fa80..5e94b40 100644
--- a/test/Tmds.LibC.Tests/ConstantsTests.cs
+++ b/test/Tmds.LibC.Tests/ConstantsTests.cs
@@ -34,7 +34,9 @@ public unsafe void Constants()
                     "linux/if_packet.h",
                     "sys/mman.h",
                     "linux/mman.h",
-                    "sys/eventfd.h"
+                    "sys/eventfd.h",
+                    "linux/stat.h",
+                    "linux/openat2.h"
                 })
                 {
                     if (TestEnvironment.Current.SupportsHeader(header) == false)
@@ -53,7 +55,8 @@ public unsafe void Constants()
                     if (name == "MS_NOUSER" || // glibc defines it as 1 << 31, while it should be 1U << 31.
                         name == "errno" ||
                         name == "SIGRTMAX" ||
-                        name == "SIGRTMIN")
+                        name == "SIGRTMIN" ||
+                        (name == "SOMAXCONN" && TestEnvironment.Current.Rid == TestEnvironment.TravisRid)) // SOMAXCONN was increased in recent kernels
                     {
                         continue;
                     }
diff --git a/test/Tmds.LibC.Tests/TestEnvironment.cs b/test/Tmds.LibC.Tests/TestEnvironment.cs
index 4e930dd..9a1d5d0 100644
--- a/test/Tmds.LibC.Tests/TestEnvironment.cs
+++ b/test/Tmds.LibC.Tests/TestEnvironment.cs
@@ -6,17 +6,24 @@ namespace Tmds.Linux.Tests
 {
     class TestEnvironment
     {
+        public const string TravisRid = "ubuntu-16.04";
+        public const string TmdsRid = "fedora-32";
+
         private string[] _unsupportedStructs;
         private string[] _unsupportedConstants;
         private string[] _unsupportedFunctions;
         private string[] _unsupportedHeaders;
 
+        public string Rid { get; set; }
+
         private TestEnvironment(
+            string rid,
             string[] unsupportedStructs = null,
             string[] unsupportedConstants = null,
             string[] unsupportedFunctions = null,
             string[] unsupportedHeaders = null)
         {
+            Rid = rid;
             _unsupportedConstants = unsupportedConstants;
             _unsupportedStructs = unsupportedStructs;
             _unsupportedFunctions = unsupportedFunctions;
@@ -79,9 +86,10 @@ static TestEnvironment()
         {
             string rid = GetRid();
             Console.WriteLine($"Test Environment: {rid}");
-            if (rid == "fedora-31")
+            if (rid == TmdsRid)
             {
                 Current = new TestEnvironment(
+                    rid,
                     unsupportedStructs: new string[]
                     { },
                     unsupportedConstants: new string[]
@@ -148,22 +156,70 @@ static TestEnvironment()
                         "IORING_UNREGISTER_FILES",
                         "IORING_REGISTER_EVENTFD",
                         "IORING_UNREGISTER_EVENTFD",
+                        "IOSQE_IO_HARDLINK",
+                        "IOSQE_ASYNC",
+                        "IOSQE_BUFFER_SELECT",
+                        "IORING_SETUP_CQSIZE",
+                        "IORING_SETUP_CLAMP",
+                        "IORING_SETUP_ATTACH_WQ",
+                        "IORING_OP_TIMEOUT",
+                        "IORING_OP_TIMEOUT_REMOVE",
+                        "IORING_OP_ACCEPT",
+                        "IORING_OP_ASYNC_CANCEL",
+                        "IORING_OP_LINK_TIMEOUT",
+                        "IORING_OP_CONNECT",
+                        "IORING_OP_FALLOCATE",
+                        "IORING_OP_OPENAT",
+                        "IORING_OP_CLOSE",
+                        "IORING_OP_FILES_UPDATE",
+                        "IORING_OP_STATX",
+                        "IORING_OP_READ",
+                        "IORING_OP_WRITE",
+                        "IORING_OP_FADVISE",
+                        "IORING_OP_MADVISE",
+                        "IORING_OP_SEND",
+                        "IORING_OP_RECV",
+                        "IORING_OP_OPENAT2",
+                        "IORING_OP_EPOLL_CTL",
+                        "IORING_OP_SPLICE",
+                        "IORING_OP_PROVIDE_BUFFERS",
+                        "IORING_OP_REMOVE_BUFFERS",
+                        "IORING_TIMEOUT_ABS",
+                        "SPLICE_F_FD_IN_FIXED",
+                        "IORING_CQE_F_BUFFER",
+                        "IORING_CQE_BUFFER_SHIFT",
+                        "IORING_FEAT_SINGLE_MMAP",
+                        "IORING_FEAT_NODROP",
+                        "IORING_FEAT_SUBMIT_STABLE",
+                        "IORING_FEAT_RW_CUR_POS",
+                        "IORING_FEAT_CUR_PERSONALITY",
+                        "IORING_FEAT_FAST_POLL",
+                        "IORING_REGISTER_FILES_UPDATE",
+                        "IORING_REGISTER_EVENTFD_ASYNC",
+                        "IORING_REGISTER_PROBE",
+                        "IORING_REGISTER_PERSONALITY",
+                        "IORING_UNREGISTER_PERSONALITY",
+                        "IO_URING_OP_SUPPORTED",
                     },
                     unsupportedHeaders: new string[]
                     { },
                     unsupportedFunctions: new string[]
                     { });
             }
-            else if (rid == "ubuntu-16.04") // Travis
+            else if (rid == TravisRid) // Travis
             {
                 Current = new TestEnvironment(
-                    unsupportedStructs: new string[] 
+                    rid,
+                    unsupportedStructs: new string[]
                     {
                         "statx_timestamp",
                         "statx"
                     },
                     unsupportedConstants: null,
-                    unsupportedHeaders: null,
+                    unsupportedHeaders: new string[]
+                    {
+                        "linux/openat2.h"
+                    },
                     unsupportedFunctions: new string[]
                     {
                         "mlock2",
@@ -173,7 +229,7 @@ static TestEnvironment()
             }
             else
             {
-                Current = new TestEnvironment();
+                Current = new TestEnvironment(rid);
             }
         }