diff --git a/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
index 388a6580..e91e9767 100644
--- a/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
+++ b/src/client/linux/minidump_writer/linux_dumper_unittest_helper.cc
@@ -48,10 +48,10 @@
 #endif
 
 void *thread_function(void *data) {
-  pid_t thread_id = syscall(SYS_gettid);
-  register pid_t *thread_id_ptr asm(TID_PTR_REGISTER) = &thread_id;
+  volatile pid_t thread_id = syscall(SYS_gettid);
+  register volatile pid_t *thread_id_ptr asm(TID_PTR_REGISTER) = &thread_id;
   while (true)
-    asm("" : : "r" (thread_id_ptr));
+    asm volatile ("" : : "r" (thread_id_ptr));
   return NULL;
 }