diff --git a/lld/test/wasm/lto/thinlto-shared-memory-atomics.ll b/lld/test/wasm/lto/thinlto-shared-memory-atomics.ll
new file mode 100644
index 000000000000..0eb54034511d
--- /dev/null
+++ b/lld/test/wasm/lto/thinlto-shared-memory-atomics.ll
@@ -0,0 +1,40 @@
+; RUN: split-file %s %t
+; RUN: opt -module-summary %t/main.ll -o %t.main.o
+; RUN: opt -module-summary %t/empty.ll -o %t.empty.o
+; RUN: wasm-ld --shared-memory %t.main.o %t.empty.o -o %t.wasm
+; RUN: llvm-nm %t.wasm | FileCheck %s
+
+; This test ensures that when an unused function with target-features="+atomics,+bulk-memory"
+; is stripped during ThinLTO, the resulting empty module does not fall back to generic TargetMachine
+; features and incorrectly omit the atomics/bulk-memory features from the generated custom sections.
+;
+; Since --shared-memory is passed to wasm-ld, `+atomics` and `+bulk-memory` are propagated
+; to the LTO Config via MAttrs, bypassing the functional absence of attributes.
+
+; CHECK-NOT: error:
+; CHECK: _start
+
+;--- main.ll
+target triple = "wasm32-unknown-emscripten"
+
+define void @_start() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "target-features"="+atomics,+bulk-memory,+mutable-globals,+sign-ext" }
+
+;--- empty.ll
+target triple = "wasm32-unknown-emscripten"
+
+; Thread-local variable that forces generation of TLS layout
+@my_tls = thread_local global i32 42, align 4
+
+; This function will be removed by dropDeadSymbols because it's unused,
+; taking its target-features attribute block along with it.
+define void @unused() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "target-features"="+atomics,+bulk-memory,+mutable-globals,+sign-ext" }
diff --git a/lld/wasm/LTO.cpp b/lld/wasm/LTO.cpp
index 668cdf21ea3e..9fcb95b84b54 100644
--- a/lld/wasm/LTO.cpp
+++ b/lld/wasm/LTO.cpp
@@ -53,6 +53,19 @@ static lto::Config createConfig() {
   c.OptLevel = ctx.arg.ltoo;
   c.CPU = getCPUStr();
   c.MAttrs = getMAttrs();
+
+  // If shared memory is enabled, ensure the TargetMachine backend is
+  // instantiated with atomics and bulk-memory features so that empty
+  // partitioned ThinLTO modules don't incorrectly strip TLS variables or fall
+  // back to defaults. This bypasses a bug where deleted functions take their
+  // target-features away. This is only necessary for atomics (and not other
+  // features) because Atomics and TLS are the only features we lower away
+  // during codegen.
+  if (ctx.arg.sharedMemory) {
+    c.MAttrs.push_back("+atomics");
+    c.MAttrs.push_back("+bulk-memory");
+  }
+
   c.CGOptLevel = ctx.arg.ltoCgo;
   c.DebugPassManager = ctx.arg.ltoDebugPassManager;
   c.AlwaysEmitRegularLTOObj = !ctx.arg.ltoObjPath.empty();