diff --git a/pkgs/development/compilers/swift/compiler/default.nix b/pkgs/development/compilers/swift/compiler/default.nix
index 8e8cf798db4f24..8bd570b6450a6b 100644
--- a/pkgs/development/compilers/swift/compiler/default.nix
+++ b/pkgs/development/compilers/swift/compiler/default.nix
@@ -47,6 +47,8 @@ let
     else
       targetPlatform.darwinMinVersion;
 
+  targetDarwinPlatform = if (targetPlatform.darwinPlatform != null) then targetPlatform.darwinPlatform else "null";
+
   python3 = python3Packages.python.withPackages (p: [ p.setuptools ]); # python 3.12 compat.
 
   inherit (stdenv) hostPlatform targetPlatform;
@@ -64,8 +66,8 @@ let
       #appletvsimulator
       #watchos
       #watchsimulator
-    }.${targetPlatform.darwinPlatform}
-      or (throw "Cannot build Swift for target Darwin platform '${targetPlatform.darwinPlatform}'")
+    }.${targetDarwinPlatform}
+      or (throw "Cannot build Swift for target Darwin platform '${targetDarwinPlatform}'")
     else targetPlatform.parsed.kernel.name;
 
   # Apple Silicon uses a different CPU name in the target triple.
@@ -504,7 +506,7 @@ in stdenv.mkDerivation {
     "
     buildProject swift
 
-    '' + lib.optionalString stdenv.hostPlatform.isDarwin ''
+    '' + lib.optionalString stdenv.targetPlatform.isDarwin ''
     # Restore search paths to remove appleSwiftCore.
     export NIX_SWIFTFLAGS_COMPILE="$OLD_NIX_SWIFTFLAGS_COMPILE"
     export NIX_LDFLAGS="$OLD_NIX_LDFLAGS"
@@ -583,7 +585,7 @@ in stdenv.mkDerivation {
         #TVOS_SIMULATOR
         #WATCHOS
         #WATCHOS_SIMULATOR
-      }.${targetPlatform.darwinPlatform}}
+      }.${targetDarwinPlatform} or (throw "Cannot build Swift for target Darwin platform '${targetDarwinPlatform}'")}
 
       -DLLVM_DIR=$SWIFT_BUILD_ROOT/llvm/lib/cmake/llvm