diff --git a/utils/build_swift/build_swift/driver_arguments.py b/utils/build_swift/build_swift/driver_arguments.py
index d659c4284d84b..36d64da196cd2 100644
--- a/utils/build_swift/build_swift/driver_arguments.py
+++ b/utils/build_swift/build_swift/driver_arguments.py
@@ -417,7 +417,7 @@ def create_argument_parser():
                 'fuzzing swiftc')
 
     option('--compiler-vendor', store,
-           choices=['none', 'apple'],
+           choices=['none', 'apple', 'swiftwasm'],
            default=defaults.COMPILER_VENDOR,
            help='Compiler vendor name')
     option('--clang-compiler-version', store,
diff --git a/utils/swift_build_support/swift_build_support/products/llvm.py b/utils/swift_build_support/swift_build_support/products/llvm.py
index 1bc27bc89e38a..73d603e4d6638 100644
--- a/utils/swift_build_support/swift_build_support/products/llvm.py
+++ b/utils/swift_build_support/swift_build_support/products/llvm.py
@@ -48,6 +48,13 @@ def _compiler_vendor_flags(self):
         if self.args.compiler_vendor == "none":
             return []
 
+        if self.args.compiler_vendor == "swiftwasm":
+            return [
+                ('CLANG_VENDOR', 'SwiftWasm'),
+                ('CLANG_VENDOR_UTI', 'org.swiftwasm.compilers.llvm.clang'),
+                ('PACKAGE_VERSION', str(self.args.clang_user_visible_version))
+            ]
+
         if self.args.compiler_vendor != "apple":
             raise RuntimeError("Unknown compiler vendor?!")
 
diff --git a/utils/swift_build_support/swift_build_support/products/swift.py b/utils/swift_build_support/swift_build_support/products/swift.py
index 1e4b4feb2df9b..36e642d9b1d86 100644
--- a/utils/swift_build_support/swift_build_support/products/swift.py
+++ b/utils/swift_build_support/swift_build_support/products/swift.py
@@ -74,14 +74,22 @@ def _compiler_vendor_flags(self):
         if self.args.compiler_vendor == "none":
             return []
 
-        if self.args.compiler_vendor != "apple":
-            raise RuntimeError("Unknown compiler vendor?! Was build-script \
-updated without updating swift.py?")
-
         swift_compiler_version = ""
         if self.args.swift_compiler_version is not None:
             swift_compiler_version = self.args.swift_compiler_version
 
+        if self.args.compiler_vendor == "swiftwasm":
+            return [
+                ('SWIFT_VENDOR', 'SwiftWasm'),
+                ('SWIFT_VENDOR_UTI', 'org.swiftwasm.compilers.llvm.swift'),
+                ('SWIFT_VERSION', str(self.args.swift_user_visible_version)),
+                ('SWIFT_COMPILER_VERSION', str(swift_compiler_version)),
+            ]
+
+        if self.args.compiler_vendor != "apple":
+            raise RuntimeError("Unknown compiler vendor?! Was build-script \
+updated without updating swift.py?")
+
         return [
             ('SWIFT_VENDOR', 'Apple'),
             ('SWIFT_VENDOR_UTI', 'com.apple.compilers.llvm.swift'),
diff --git a/utils/webassembly/build-presets.ini b/utils/webassembly/build-presets.ini
index 8fca4eac9df05..f0861b4589844 100644
--- a/utils/webassembly/build-presets.ini
+++ b/utils/webassembly/build-presets.ini
@@ -8,6 +8,7 @@ cmake-cxx-launcher=%(C_CXX_LAUNCHER)s
 skip-build-benchmarks
 llvm-targets-to-build=X86;AArch64;WebAssembly
 swift-darwin-supported-archs=x86_64
+compiler-vendor=swiftwasm
 
 [preset: webassembly-install]