diff --git a/headers/private/libroot/libroot_private.h b/headers/private/libroot/libroot_private.h
index 0b1c924061..20d035a10e 100644
--- a/headers/private/libroot/libroot_private.h
+++ b/headers/private/libroot/libroot_private.h
@@ -32,6 +32,7 @@ status_t __flatten_process_args(const char* const* args, int32 argCount,
 void _call_atexit_hooks_for_range(addr_t start, addr_t size);
 void __init_env(const struct user_space_program_args *args);
 void __init_heap(void);
+void __init_heap_post_env(void);
 
 void __init_time(void);
 void __arch_init_time(struct real_time_data *data, bool setDefaults);
diff --git a/src/system/libroot/libroot_init.c b/src/system/libroot/libroot_init.c
index bceb3d9faf..7739b01828 100644
--- a/src/system/libroot/libroot_init.c
+++ b/src/system/libroot/libroot_init.c
@@ -58,6 +58,7 @@ initialize_before(image_id imageID)
 	__init_time();
 	__init_heap();
 	__init_env(__gRuntimeLoader->program_args);
+	__init_heap_post_env();
 	__init_pwd_backend();
 }
 
diff --git a/src/system/libroot/posix/malloc/arch-specific.cpp b/src/system/libroot/posix/malloc/arch-specific.cpp
index cd51a3651b..8cb1f6723b 100644
--- a/src/system/libroot/posix/malloc/arch-specific.cpp
+++ b/src/system/libroot/posix/malloc/arch-specific.cpp
@@ -119,6 +119,13 @@ __init_heap(void)
 }
 
 
+extern "C" void
+__init_heap_post_env(void)
+{
+	// no heap options available
+}
+
+
 static void
 insert_chunk(free_chunk *newChunk)
 {
diff --git a/src/system/libroot/posix/malloc_debug/heap.cpp b/src/system/libroot/posix/malloc_debug/heap.cpp
index 2dc4d90126..1b0f85f2a9 100644
--- a/src/system/libroot/posix/malloc_debug/heap.cpp
+++ b/src/system/libroot/posix/malloc_debug/heap.cpp
@@ -2,13 +2,14 @@
  * Copyright 2008-2009, Michael Lotz, mmlr@mlotz.ch.
  * Distributed under the terms of the MIT License.
  *
- * Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2011, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001, Travis Geiselbrecht. All rights reserved.
  * Distributed under the terms of the NewOS License.
  */
 
+
 #include <malloc.h>
 #include <malloc_debug.h>
 #include <stdio.h>
@@ -41,6 +42,7 @@ static bool sReuseMemory = true;
 static bool sParanoidValidation = false;
 static thread_id sWallCheckThread = -1;
 static bool sStopWallChecking = false;
+static bool sUseGuardPage = false;
 
 
 void
@@ -1817,6 +1819,25 @@ __init_heap(void)
 }
 
 
+extern "C" void
+__init_heap_post_env(void)
+{
+	const char *mode = getenv("MALLOC_DEBUG");
+	if (mode != NULL) {
+		if (strchr(mode, 'p'))
+			heap_debug_set_paranoid_validation(true);
+		if (strchr(mode, 'w'))
+			heap_debug_start_wall_checking(500);
+		else if (strchr(mode, 'W'))
+			heap_debug_start_wall_checking(100);
+		if (strchr(mode, 'g'))
+			sUseGuardPage = true;
+		if (strchr(mode, 'r'))
+			heap_debug_set_memory_reuse(false);
+	}
+}
+
+
 //	#pragma mark - Public API
 
 
@@ -1908,6 +1929,9 @@ memalign(size_t alignment, size_t size)
 void *
 malloc(size_t size)
 {
+	if (sUseGuardPage)
+		return heap_debug_malloc_with_guard_page(size);
+
 	return memalign(0, size);
 }