diff --git a/src/sync.cpp b/src/sync.cpp
--- a/src/sync.cpp
+++ b/src/sync.cpp
@@ -71,7 +71,7 @@
     std::mutex dd_mutex;
 } static lockdata;
 
-static thread_local std::unique_ptr<LockStack> lockstack;
+static thread_local LockStack g_lockstack;
 
 static void
 potential_deadlock_detected(const std::pair<void *, void *> &mismatch,
@@ -108,15 +108,11 @@
 }
 
 static void push_lock(void *c, const CLockLocation &locklocation) {
-    if (!lockstack) {
-        lockstack.reset(new LockStack);
-    }
-
     std::lock_guard<std::mutex> lock(lockdata.dd_mutex);
 
-    lockstack->push_back(std::make_pair(c, locklocation));
+    g_lockstack.push_back(std::make_pair(c, locklocation));
 
-    for (const std::pair<void *, CLockLocation> &i : (*lockstack)) {
+    for (const std::pair<void *, CLockLocation> &i : g_lockstack) {
         if (i.first == c) {
             break;
         }
@@ -125,7 +121,7 @@
         if (lockdata.lockorders.count(p1)) {
             continue;
         }
-        lockdata.lockorders[p1] = (*lockstack);
+        lockdata.lockorders[p1] = g_lockstack;
 
         std::pair<void *, void *> p2 = std::make_pair(c, i.first);
         lockdata.invlockorders.insert(p2);
@@ -137,7 +133,7 @@
 }
 
 static void pop_lock() {
-    (*lockstack).pop_back();
+    g_lockstack.pop_back();
 }
 
 void EnterCritical(const char *pszName, const char *pszFile, int nLine,
@@ -151,7 +147,7 @@
 
 std::string LocksHeld() {
     std::string result;
-    for (const std::pair<void *, CLockLocation> &i : *lockstack) {
+    for (const std::pair<void *, CLockLocation> &i : g_lockstack) {
         result += i.second.ToString() + std::string("\n");
     }
     return result;
@@ -159,7 +155,7 @@
 
 void AssertLockHeldInternal(const char *pszName, const char *pszFile, int nLine,
                             void *cs) {
-    for (const std::pair<void *, CLockLocation> &i : *lockstack) {
+    for (const std::pair<void *, CLockLocation> &i : g_lockstack) {
         if (i.first == cs) {
             return;
         }
@@ -172,7 +168,7 @@
 
 void AssertLockNotHeldInternal(const char *pszName, const char *pszFile,
                                int nLine, void *cs) {
-    for (const std::pair<void *, CLockLocation> &i : *lockstack) {
+    for (const std::pair<void *, CLockLocation> &i : g_lockstack) {
         if (i.first == cs) {
             fprintf(stderr,
                     "Assertion failed: lock %s held in %s:%i; locks held:\n%s",