diff --git a/build.sh b/build.sh
index 2949aac..649d62c 100644
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
-gcc -o bld code/build_main.cpp -g
+gcc -o bld code/build_main.cpp -g 
 ./bld
diff --git a/build_file.cpp b/build_file.cpp
index 352beea..0b908ea 100644
--- a/build_file.cpp
+++ b/build_file.cpp
@@ -20,13 +20,13 @@ int CompileFiles(Strs cc, Strs files) {
     Str exe = FilenameWithoutExt(files[0]);
     Str filestr = Merge(files);
     if (cc == "gcc") {
-        result = OS_SystemF("g++ -o %Q.exe %Q -g -Wno-write-strings", exe, filestr);
+        result = OS_SystemF("g++ -o %Q.exe %Q -g -Wno-write-strings -fsanitize=address", exe, filestr);
     }
     else if (cc == "clang") {
-        result = OS_SystemF("clang++ -std=c++11 -o %Q.exe %Q -g -Wno-writable-strings", exe, filestr);
+        result = OS_SystemF("clang++ -std=c++11 -o %Q.exe %Q -g -Wno-writable-strings -fsanitize=address", exe, filestr);
     }
     else {
-        result = OS_SystemF("cl -Fe:%Q.exe %Q -Zi -WX -W3 -wd4200 -diagnostics:column -nologo -D_CRT_SECURE_NO_WARNINGS", exe, filestr);
+        result = OS_SystemF("cl -Fe:%Q.exe %Q -Zi -WX -W3 -wd4200 -diagnostics:column -nologo -D_CRT_SECURE_NO_WARNINGS -fsanitize=address -RTC1", exe, filestr);
     }
     if (result == 0) result = OS_SystemF(IF_WINDOWS_ELSE("", "./") "%Q.exe", exe);
     return result;
diff --git a/code/arena.c b/code/arena.c
index ce88687..13d2b86 100644
--- a/code/arena.c
+++ b/code/arena.c
@@ -33,6 +33,40 @@ MA_API void MA_MemoryCopy(void *dst, void *src, size_t size) {
     #endif
 #endif
 
+// Marks memory region [addr, addr+size) as unaddressable.
+// This memory must be previously allocated by the user program. Accessing
+// addresses in this region from instrumented code is forbidden until
+// this region is unpoisoned. This function is not guaranteed to poison
+// the whole region - it may poison only subregion of [addr, addr+size) due
+// to ASan alignment restrictions.
+// Method is NOT thread-safe in the sense that no two threads can
+// (un)poison memory in the same memory region simultaneously.
+void __asan_poison_memory_region(void const volatile *addr, size_t size);
+// Marks memory region [addr, addr+size) as addressable.
+// This memory must be previously allocated by the user program. Accessing
+// addresses in this region is allowed until this region is poisoned again.
+// This function may unpoison a superregion of [addr, addr+size) due to
+// ASan alignment restrictions.
+// Method is NOT thread-safe in the sense that no two threads can
+// (un)poison memory in the same memory region simultaneously.
+void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
+
+// User code should use macros instead of functions.
+#if defined(__clang__)
+    #if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer)
+        #define ASAN_POISON_MEMORY_REGION(addr, size) \
+            __asan_poison_memory_region((addr), (size))
+        #define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
+            __asan_unpoison_memory_region((addr), (size))
+    #endif
+#endif
+#ifndef ASAN_POISON_MEMORY_REGION
+    #define ASAN_POISON_MEMORY_REGION(addr, size) \
+        ((void)(addr), (void)(size))
+    #define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
+        ((void)(addr), (void)(size))
+#endif
+
 MA_API size_t MA_GetAlignOffset(size_t size, size_t align) {
     size_t mask = align - 1;
     size_t val = size & mask;
@@ -71,7 +105,9 @@ MA_StaticFunc uint8_t *MV__AdvanceCommit(MV_Memory *m, size_t *commit_size, size
 MA_API void MA_PopToPos(MA_Arena *arena, size_t pos) {
     MA_ASSERT(arena->len >= arena->base_len);
     pos = MA_CLAMP(pos, arena->base_len, arena->len);
+    size_t size = arena->len - pos;
     arena->len = pos;
+    ASAN_POISON_MEMORY_REGION(arena->memory.data + pos, size);
 }
 
 MA_API void MA_PopSize(MA_Arena *arena, size_t size) {
@@ -122,6 +158,7 @@ MA_API void *MA_PushSizeNonZeroed(MA_Arena *a, size_t size) {
     uint8_t *result = a->memory.data + aligned_len;
     a->len += size_with_alignment;
     MA_ASSERT(a->len <= a->memory.commit);
+    ASAN_UNPOISON_MEMORY_REGION(result, a->len);
     return (void *)result;
 }
 
@@ -133,6 +170,7 @@ MA_API void *MA_PushSize(MA_Arena *arena, size_t size) {
 
 MA_API void MA_InitEx(MA_Arena *a, size_t reserve) {
     a->memory = MV_Reserve(reserve);
+    ASAN_POISON_MEMORY_REGION(a->memory.data, a->memory.reserve);
     a->alignment = MA_DEFAULT_ALIGNMENT;
 }
 
diff --git a/test/test_array.cpp b/test/test_array.cpp
index 7a66766..a87dcac 100644
--- a/test/test_array.cpp
+++ b/test/test_array.cpp
@@ -47,6 +47,7 @@ void TestRemoveForLoop() {
     IO_Assert(array[5] == 6);
     IO_Assert(array[3] == 3);
     IO_Assert(array.len == 99);
+    array.dealloc();
 }
 
 void TestBasic() {
@@ -114,6 +115,8 @@ void TestCopy() {
 
     IO_Assert(b.cap == b.len && b.len == a.len);
     IO_Assert(a.len == c.len && a.cap == c.cap);
+
+    a.dealloc();
 }
 
 int main() {
diff --git a/test/test_table.cpp b/test/test_table.cpp
index 9ae6d22..d723879 100644
--- a/test/test_table.cpp
+++ b/test/test_table.cpp
@@ -34,6 +34,7 @@ void TestStrings() {
     IO_Assert(table.gets("1")->i == 1);
     IO_Assert(table.gets("2")->i == 2);
     IO_Assert(table.gets("3")->i == 3);
+    table.dealloc();
 }
 
 int main() {