diff --git a/dqn.h b/dqn.h
index d204306..4331805 100644
--- a/dqn.h
+++ b/dqn.h
@@ -246,6 +246,11 @@
 //
 //     DQN_ASAN_VET_POISON 1
 //
+// - Define this macro to the size of the guard memory reserved before and after
+//   allocations made that are poisoned to protect against out-of-bounds memory
+//   accesses. By default the library sets the guard to 128 bytes.
+//
+//     DQN_ASAN_POISON_GUARD_SIZE 128
 
 // NOTE: Dqn_Strings ===============================================================================
 // [$CSTR] Dqn_CString8       |                             | C-string helpers
diff --git a/dqn_debug.h b/dqn_debug.h
index 069258a..77eda87 100644
--- a/dqn_debug.h
+++ b/dqn_debug.h
@@ -38,9 +38,13 @@
     #define DQN_ASAN_POISON_VET 0
 #endif
 
-#if !defined(DQN_ASAN_POISON_ALIGNMENT)
-    #define DQN_ASAN_POISON_ALIGNMENT 8
+#define DQN_ASAN_POISON_ALIGNMENT 8
+#if !defined(DQN_ASAN_POISON_GUARD_SIZE)
+    #define DQN_ASAN_POISON_GUARD_SIZE 128
 #endif
+static_assert(Dqn_IsPowerOfTwoAligned(DQN_ASAN_POISON_GUARD_SIZE, DQN_ASAN_POISON_ALIGNMENT),
+              "ASAN poison guard size must be a power-of-two and aligned to ASAN's alignment"
+              "requirement (8 bytes)");
 
 // NOTE: MSVC does not support the feature detection macro for instance so we
 // compile it out
@@ -48,7 +52,7 @@
     #define __has_feature(x) 0
 #endif
 
-// NOTE: [$ASAN] Dqn_Asan ========================================================================== ===
+// NOTE: [$ASAN] Dqn_Asan ==========================================================================
 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
     #include <sanitizer/asan_interface.h>
 #endif
diff --git a/dqn_helpers.cpp b/dqn_helpers.cpp
index b54a35b..e4b7f3e 100644
--- a/dqn_helpers.cpp
+++ b/dqn_helpers.cpp
@@ -844,8 +844,10 @@ DQN_API Dqn_Library *Dqn_Library_Init()
     Dqn_Log_DebugF("Dqn Library initialised:\n");
     Dqn_Print_StdLnF(Dqn_PrintStd_Err, "  OS Page Size/Alloc Granularity: %$$_I32u/%$$_I32u", result->os_page_size, result->os_alloc_granularity);
 
-    if (DQN_ASAN_POISON)
+    if (DQN_ASAN_POISON) {
         Dqn_Print_StdLnF(Dqn_PrintStd_Err, "  ASAN manual poisoning%s", DQN_ASAN_VET_POISON ? " (+vet sanity checks)" : "");
+        Dqn_Print_StdLnF(Dqn_PrintStd_Err, "  ASAN poison guard size: %$$_I32u", DQN_ASAN_POISON_GUARD_SIZE);
+    }
 
     #if defined(DQN_LEAK_TRACING)
     Dqn_Print_StdLnF(Dqn_PrintStd_Err, "  Allocation leak tracing");
diff --git a/dqn_memory.cpp b/dqn_memory.cpp
index 8a82b3b..57c0cb1 100644
--- a/dqn_memory.cpp
+++ b/dqn_memory.cpp
@@ -179,7 +179,7 @@ DQN_API Dqn_MemBlockSizeRequiredResult Dqn_MemBlock_SizeRequired(Dqn_MemBlock co
         // is always guarded with poison-ed memory to prevent read/writes behind
         // the block of memory.
         if ((block_flags & Dqn_MemBlockFlag_AllocsAreContiguous) == 0) {
-            result.alloc_size = Dqn_AlignUpPowerOfTwo(size + g_dqn_library->os_page_size, DQN_ASAN_POISON_ALIGNMENT);
+            result.alloc_size = Dqn_AlignUpPowerOfTwo(size + DQN_ASAN_POISON_GUARD_SIZE, DQN_ASAN_POISON_ALIGNMENT);
         }
         ptr_alignment = DQN_MAX(alignment, DQN_ASAN_POISON_ALIGNMENT);
     }
@@ -199,8 +199,8 @@ DQN_API Dqn_MemBlockSizeRequiredResult Dqn_MemBlock_SizeRequired(Dqn_MemBlock co
 
 Dqn_usize Dqn_MemBlock_MetadataSize()
 {
-    Dqn_usize init_poison_page = DQN_ASAN_POISON ? g_dqn_library->os_page_size : 0;
-    Dqn_usize poison_alignment = DQN_ASAN_POISON ? DQN_ASAN_POISON_ALIGNMENT : 0;
+    Dqn_usize init_poison_page = DQN_ASAN_POISON ? DQN_ASAN_POISON_GUARD_SIZE : 0;
+    Dqn_usize poison_alignment = DQN_ASAN_POISON ? DQN_ASAN_POISON_ALIGNMENT  : 0;
     Dqn_usize result           = Dqn_AlignUpPowerOfTwo(sizeof(Dqn_MemBlock), poison_alignment) + init_poison_page;
     return result;
 }
@@ -236,7 +236,7 @@ DQN_API Dqn_MemBlock *Dqn_MemBlock_Init(Dqn_usize reserve, Dqn_usize commit, uin
             DQN_ASSERT(Dqn_IsPowerOfTwoAligned(result->data, DQN_ASAN_POISON_ALIGNMENT));
             DQN_ASSERT(Dqn_IsPowerOfTwoAligned(result->size, DQN_ASAN_POISON_ALIGNMENT));
             void *poison_ptr          = DQN_CAST(void *)Dqn_AlignUpPowerOfTwo(DQN_CAST(char *)result + sizeof(Dqn_MemBlock), DQN_ASAN_POISON_ALIGNMENT);
-            Dqn_usize bytes_to_poison = g_dqn_library->os_page_size + result->size;
+            Dqn_usize bytes_to_poison = DQN_ASAN_POISON_GUARD_SIZE + result->size;
             Dqn_ASAN_PoisonMemoryRegion(poison_ptr, bytes_to_poison);
         }
     }