diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index 77247d269808..d84cfccd46f6 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -124,6 +124,8 @@ let
             "ucrt"
           else if final.isMinGW then
             "msvcrt"
+          else if final.isCygwin then
+            "cygwin"
           else if final.isWasi then
             "wasilibc"
           else if final.isWasm && !final.isWasi then
@@ -183,7 +185,7 @@ let
             sharedLibrary =
               if final.isDarwin then
                 ".dylib"
-              else if final.isWindows then
+              else if (final.isWindows || final.isCygwin) then
                 ".dll"
               else
                 ".so";
@@ -191,7 +193,7 @@ let
           // {
             staticLibrary = if final.isWindows then ".lib" else ".a";
             library = if final.isStatic then final.extensions.staticLibrary else final.extensions.sharedLibrary;
-            executable = if final.isWindows then ".exe" else "";
+            executable = if (final.isWindows || final.isCygwin) then ".exe" else "";
           };
         # Misc boolean options
         useAndroidPrebuilt = false;
@@ -204,6 +206,7 @@ let
             {
               linux = "Linux";
               windows = "Windows";
+              cygwin = "CYGWIN_NT";
               darwin = "Darwin";
               netbsd = "NetBSD";
               freebsd = "FreeBSD";
@@ -603,7 +606,7 @@ let
               "openbsd"
             else if final.isSunOS then
               "sunos"
-            else if final.isWindows then
+            else if (final.isWindows || final.isCygwin) then
               "win32"
             else
               null;
diff --git a/lib/systems/examples.nix b/lib/systems/examples.nix
index 9a53dac073ae..cdd28b1ddde1 100644
--- a/lib/systems/examples.nix
+++ b/lib/systems/examples.nix
@@ -388,6 +388,10 @@ rec {
     useLLVM = true;
   };
 
+  x86_64-cygwin = {
+    config = "x86_64-pc-cygwin";
+  };
+
   # BSDs
 
   aarch64-freebsd = {
diff --git a/lib/systems/inspect.nix b/lib/systems/inspect.nix
index 65fdb9ee1959..ad6ff2b380a8 100644
--- a/lib/systems/inspect.nix
+++ b/lib/systems/inspect.nix
@@ -337,8 +337,7 @@ rec {
       kernel = kernels.windows;
     };
     isCygwin = {
-      kernel = kernels.windows;
-      abi = abis.cygnus;
+      kernel = kernels.cygwin;
     };
     isMinGW = {
       kernel = kernels.windows;
diff --git a/lib/systems/parse.nix b/lib/systems/parse.nix
index 0dfd91b7bb76..bbb0fa9d5582 100644
--- a/lib/systems/parse.nix
+++ b/lib/systems/parse.nix
@@ -42,6 +42,7 @@ let
     isLinux
     isPower64
     isWindows
+    isCygwin
     ;
 
   inherit (lib.types)
@@ -617,6 +618,10 @@ rec {
         execFormat = pe;
         families = { };
       };
+      cygwin = {
+        execFormat = pe;
+        families = { };
+      };
       ghcjs = {
         execFormat = unknown;
         families = { };
@@ -650,7 +655,6 @@ rec {
   types.abi = enum (attrValues abis);
 
   abis = setTypes types.openAbi {
-    cygnus = { };
     msvc = { };
 
     # Note: eabi is specific to ARM and PowerPC.
@@ -783,11 +787,11 @@ rec {
           throw "system string '${lib.concatStringsSep "-" l}' with 1 component is ambiguous";
       "2" = # We only do 2-part hacks for things Nix already supports
         if elemAt l 1 == "cygwin" then
-          {
-            cpu = elemAt l 0;
-            kernel = "windows";
-            abi = "cygnus";
-          }
+          mkSkeletonFromList [
+            (elemAt l 0)
+            "pc"
+            "cygwin"
+          ]
         # MSVC ought to be the default ABI so this case isn't needed. But then it
         # becomes difficult to handle the gnu* variants for Aarch32 correctly for
         # minGW. So it's easier to make gnu* the default for the MinGW, but
@@ -851,6 +855,13 @@ rec {
               else
                 elemAt l 2;
           }
+        # lots of tools expect a triplet for Cygwin, even though the vendor is just "pc"
+        else if elemAt l 2 == "cygwin" then
+          {
+            cpu = elemAt l 0;
+            vendor = elemAt l 1;
+            kernel = "cygwin";
+          }
         else
           throw "system string '${lib.concatStringsSep "-" l}' with 3 components is ambiguous";
       "4" = {
@@ -891,7 +902,7 @@ rec {
             getVendor args.vendor
           else if isDarwin parsed then
             vendors.apple
-          else if isWindows parsed then
+          else if (isWindows parsed || isCygwin parsed) then
             vendors.pc
           else
             vendors.unknown;
@@ -933,12 +944,7 @@ rec {
       abi,
       ...
     }:
-    if abi == abis.cygnus then
-      "${cpu.name}-cygwin"
-    else if kernel.families ? darwin then
-      "${cpu.name}-darwin"
-    else
-      "${cpu.name}-${kernelName kernel}";
+    if kernel.families ? darwin then "${cpu.name}-darwin" else "${cpu.name}-${kernelName kernel}";
 
   tripleFromSystem =
     {
diff --git a/lib/tests/systems.nix b/lib/tests/systems.nix
index 3bddf78dea19..642339e792fd 100644
--- a/lib/tests/systems.nix
+++ b/lib/tests/systems.nix
@@ -49,6 +49,7 @@ lib.runTests (
       ++ illumos
       ++ wasi
       ++ windows
+      ++ cygwin
       ++ embedded
       ++ mmix
       ++ js
@@ -202,8 +203,6 @@ lib.runTests (
       "x86_64-openbsd"
     ];
     testwindows = mseteq windows [
-      "i686-cygwin"
-      "x86_64-cygwin"
       "aarch64-windows"
       "i686-windows"
       "x86_64-windows"