diff --git a/src/stacktrace_libunwind-inl.h b/src/stacktrace_libunwind-inl.h
index 0dc14c6..0b20d23 100644
--- a/src/stacktrace_libunwind-inl.h
+++ b/src/stacktrace_libunwind-inl.h
@@ -37,7 +37,7 @@
 #define UNW_LOCAL_ONLY
 #include <libunwind.h>
 }
-#include "glog/raw_logging.h"
+#include <glog/raw_logging.h>
 #include "stacktrace.h"
 
 _START_GOOGLE_NAMESPACE_
@@ -49,7 +49,9 @@
 // recursive request, we'd end up with infinite recursion or deadlock.
 // Luckily, it's safe to ignore those subsequent traces.  In such
 // cases, we return 0 to indicate the situation.
-static bool g_now_entering = false;
+// We can use the GCC __thread syntax here since libunwind is not supported on
+// Windows.
+static __thread bool g_tl_entered; // Initialized to false.
 
 // If you change this function, also change GetStackFrames below.
 int GetStackTrace(void** result, int max_depth, int skip_count) {
@@ -58,29 +60,33 @@
   unw_cursor_t cursor;
   unw_context_t uc;
 
-  if (sync_val_compare_and_swap(&g_now_entering, false, true)) {
+  if (g_tl_entered) {
     return 0;
   }
+  g_tl_entered = true;
 
   unw_getcontext(&uc);
   RAW_CHECK(unw_init_local(&cursor, &uc) >= 0, "unw_init_local failed");
   skip_count++;         // Do not include the "GetStackTrace" frame
 
   while (n < max_depth) {
-    int ret = unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip);
-    if (ret < 0)
+    int ret =
+        unw_get_reg(&cursor, UNW_REG_IP, reinterpret_cast<unw_word_t *>(&ip));
+    if (ret < 0) {
       break;
+    }
     if (skip_count > 0) {
       skip_count--;
     } else {
       result[n++] = ip;
     }
     ret = unw_step(&cursor);
-    if (ret <= 0)
+    if (ret <= 0) {
       break;
+    }
   }
 
-  g_now_entering = false;
+  g_tl_entered = false;
   return n;
 }