diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.h b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
index 47b02b149d32beec050c9b69653f58920f3b8dfc..11ee5902462431fb80db24fe1b134decdf869fe3 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
@@ -727,7 +727,7 @@ class LoadedModule {
 // filling this information.
 class ListOfModules {
  public:
-  ListOfModules() : modules_(kInitialCapacity) {}
+  ListOfModules() : initialized(false) {}
   ~ListOfModules() { clear(); }
   void init();
   const LoadedModule *begin() const { return modules_.begin(); }
@@ -745,10 +745,15 @@ class ListOfModules {
     for (auto &module : modules_) module.clear();
     modules_.clear();
   }
+  void clearOrInit() {
+    initialized ? clear() : modules_.Initialize(kInitialCapacity);
+    initialized = true;
+  }
 
-  InternalMmapVector<LoadedModule> modules_;
+  InternalMmapVectorNoCtor<LoadedModule> modules_;
   // We rarely have more than 16K loaded modules.
   static const uptr kInitialCapacity = 1 << 14;
+  bool initialized;
 };
 
 // Callback type for iterating over a set of memory ranges.
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index da715dc6cdbfce8b9116bdcd3f8da73175b46076..0f420875d43723ec892a4148f0402a2d0dafa3fb 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -424,7 +424,7 @@ typedef ElfW(Phdr) Elf_Phdr;
 # endif
 
 struct DlIteratePhdrData {
-  InternalMmapVector<LoadedModule> *modules;
+  InternalMmapVectorNoCtor<LoadedModule> *modules;
   bool first;
 };
 
@@ -473,13 +473,13 @@ static bool requiresProcmaps() {
 #endif
 }
 
-static void procmapsInit(InternalMmapVector<LoadedModule> *modules) {
+static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
   MemoryMappingLayout memory_mapping(false);
   memory_mapping.DumpListOfModules(modules);
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   if (requiresProcmaps()) {
     procmapsInit(&modules_);
   } else {
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
index 1570ae277de941b043c09f8fd3d69cda4c37f3ab..cd63cb42f63713f10c8e36a5cd5114186d0b57c4 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
@@ -411,7 +411,7 @@ void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   MemoryMappingLayout memory_mapping(false);
   memory_mapping.DumpListOfModules(&modules_);
 }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
index 96d0b2f9de73136f7a17d4bd16910f20a0f34c68..d462ad8414d8781656a56bd66bbec78fedec1b5d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h
@@ -76,7 +76,7 @@ class MemoryMappingLayout {
   static void CacheMemoryMappings();
 
   // Adds all mapped objects into a vector.
-  void DumpListOfModules(InternalMmapVector<LoadedModule> *modules);
+  void DumpListOfModules(InternalMmapVectorNoCtor<LoadedModule> *modules);
 
  private:
   void LoadFromCache();
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc
index 30663e8c67523550bbcb73db19fbc40e9b4a0bb0..b9298d4cce2e0d67ea010328d175f01ed13608ad 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc
@@ -120,7 +120,7 @@ void MemoryMappingLayout::LoadFromCache() {
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
   InternalScopedString module_name(kMaxPathLength);
   MemoryMappedSegment segment(module_name.data(), module_name.size());
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc
index 786876f04544bba5421f461127567ae330fe1a66..3b98ff0957863265a00e6cb4c3e060a38294ca65 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc
@@ -353,7 +353,7 @@ bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
   InternalScopedString module_name(kMaxPathLength);
   MemoryMappedSegment segment(module_name.data(), kMaxPathLength);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
index a144db28c33ac349c4c4071fee8c4a741be89a98..84065aa0e876f77daf86b5a3b6b573cf56215d34 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
@@ -524,7 +524,7 @@ static uptr GetPreferredBase(const char *modname) {
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   HANDLE cur_process = GetCurrentProcess();
 
   // Query the list of modules.  Start by assuming there are no more than 256