diff --git a/clang/lib/Driver/ToolChains/WebAssembly.cpp b/clang/lib/Driver/ToolChains/WebAssembly.cpp
index a1c4cd9ef9c79..016b70b1c2ede 100644
--- a/clang/lib/Driver/ToolChains/WebAssembly.cpp
+++ b/clang/lib/Driver/ToolChains/WebAssembly.cpp
@@ -459,6 +459,9 @@ SanitizerMask WebAssembly::getSupportedSanitizers() const {
   if (getTriple().isOSEmscripten()) {
     Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
   }
+  // -fsanitize=function places two words before the function label, which are
+  // -unsupported.
+  Res &= ~SanitizerKind::Function;
   return Res;
 }
 
diff --git a/clang/test/Driver/wasm-toolchain.c b/clang/test/Driver/wasm-toolchain.c
index f391b2802308d..bfe696d7846e7 100644
--- a/clang/test/Driver/wasm-toolchain.c
+++ b/clang/test/Driver/wasm-toolchain.c
@@ -146,6 +146,9 @@
 // CHECK-ASAN-EMSCRIPTEN: "-fsanitize=address"
 // CHECK-ASAN-EMSCRIPTEN: "-fsanitize-address-globals-dead-stripping"
 
+// RUN: %clang -### %s -fsanitize=function --target=wasm32-unknown-emscripten 2>&1 | FileCheck --check-prefix=FUNCTION %s
+// FUNCTION: error: unsupported option '-fsanitize=function' for target 'wasm32-unknown-emscripten'
+
 // Basic exec-model tests.
 
 // RUN: %clang -### %s --target=wasm32-unknown-unknown --sysroot=%s/no-sysroot-there -mexec-model=command 2>&1 \