diff --git a/src/jsc/bindings/c-bindings.cpp b/src/jsc/bindings/c-bindings.cpp
index a20749bef69..1b42f7dc364 100644
--- a/src/jsc/bindings/c-bindings.cpp
+++ b/src/jsc/bindings/c-bindings.cpp
@@ -933,9 +933,11 @@ static struct sigaction previous_actions[NSIG];
     M(SIGIO);
 
 #if OS(LINUX)
+// SIGPWR is intentionally excluded: JSC uses it for GC thread suspend/resume
+// on Linux (see WTF/wtf/posix/ThreadingPOSIX.cpp). Replacing that handler here
+// makes the next GC-sent SIGPWR terminate the process.
 #define FOR_EACH_LINUX_ONLY_SIGNAL(M) \
     M(SIGPOLL);                       \
-    M(SIGPWR);                        \
     M(SIGSTKFLT);
 
 #endif
diff --git a/src/jsc/bindings/wtf-bindings.cpp b/src/jsc/bindings/wtf-bindings.cpp
index 0d4968f805f..8b09b5a8665 100644
--- a/src/jsc/bindings/wtf-bindings.cpp
+++ b/src/jsc/bindings/wtf-bindings.cpp
@@ -61,7 +61,7 @@ extern "C" int uv_tty_reset_mode(void)
 
 static void uv__tty_make_raw(struct termios* tio)
 {
-    assert(tio != NULL);
+    ASSERT(tio != NULL);
 
 #if defined __sun || defined __MVS__
     /*
diff --git a/test/js/bun/spawn/spawnSync.test.ts b/test/js/bun/spawn/spawnSync.test.ts
index bb60b9cad9e..701413ba817 100644
--- a/test/js/bun/spawn/spawnSync.test.ts
+++ b/test/js/bun/spawn/spawnSync.test.ts
@@ -40,4 +40,31 @@ describe("spawnSync", () => {
   it.skipIf(!isPosix)("should use spawnSync optimizations when possible", () => {
     expect([join(import.meta.dir, "spawnSync-counters-fixture.ts")]).toRun();
   });
+
+  // On Linux, JSC uses SIGPWR to suspend/resume threads for GC. The spawnSync
+  // signal-forwarding table used to include SIGPWR, so a GC that fired while
+  // (or after) spawnSync ran would terminate the process with signal 30.
+  it.skipIf(process.platform !== "linux")("does not clobber the GC thread-suspend signal handler", () => {
+    const result = Bun.spawnSync({
+      cmd: [
+        bunExe(),
+        "-e",
+        `
+          for (let i = 0; i < 50; i++) {
+            Bun.spawnSync({ cmd: ["true"] });
+            Bun.gc(true);
+          }
+          for (let i = 0; i < 50; i++) {
+            Bun.spawnSync({ cmd: ["true"] });
+          }
+          Bun.gc(true);
+        `,
+      ],
+      env: bunEnv,
+      stdout: "inherit",
+      stderr: "inherit",
+    });
+    expect(result.signalCode).toBeFalsy();
+    expect(result.exitCode).toBe(0);
+  });
 });