diff --git a/include/libtorrent/stack_allocator.hpp b/include/libtorrent/stack_allocator.hpp
index f12f4cb91..2fdd4c4f3 100644
--- a/include/libtorrent/stack_allocator.hpp
+++ b/include/libtorrent/stack_allocator.hpp
@@ -62,6 +62,7 @@ namespace libtorrent { namespace aux
 		int copy_buffer(char const* buf, int size)
 		{
 			int ret = int(m_storage.size());
+			if (size < 1) return -1;
 			m_storage.resize(ret + size);
 			memcpy(&m_storage[ret], buf, size);
 			return ret;
@@ -69,6 +70,7 @@ namespace libtorrent { namespace aux
 
 		int allocate(int bytes)
 		{
+			if (bytes < 1) return -1;
 			int ret = int(m_storage.size());
 			m_storage.resize(ret + bytes);
 			return ret;
@@ -76,14 +78,14 @@ namespace libtorrent { namespace aux
 
 		char* ptr(int idx)
 		{
-			TORRENT_ASSERT(idx >= 0);
+			if(idx < 0) return NULL;
 			TORRENT_ASSERT(idx < int(m_storage.size()));
 			return &m_storage[idx];
 		}
 
 		char const* ptr(int idx) const
 		{
-			TORRENT_ASSERT(idx >= 0);
+			if(idx < 0) return NULL;
 			TORRENT_ASSERT(idx < int(m_storage.size()));
 			return &m_storage[idx];
 		}
diff --git a/test/test_stack_allocator.cpp b/test/test_stack_allocator.cpp
index 62b1971f2..90f07f380 100644
--- a/test/test_stack_allocator.cpp
+++ b/test/test_stack_allocator.cpp
@@ -59,6 +59,14 @@ TORRENT_TEST(copy_buffer)
 	a.allocate(100000);
 
 	TEST_CHECK(strcmp(a.ptr(idx1), "testing") == 0);
+
+	// attempt zero size allocation
+	int const idx2 = a.copy_buffer("nothing", 0);
+	TEST_CHECK(idx2 == -1);
+
+	// attempt to get a pointer after zero allocation
+	char* ptr = a.ptr(idx2);
+	TEST_CHECK(ptr == NULL);
 }
 
 TORRENT_TEST(allocate)
@@ -75,6 +83,14 @@ TORRENT_TEST(allocate)
 	ptr = a.ptr(idx1);
 	for (int i = 0; i < 100; ++i)
 		TEST_CHECK(ptr[i] == char(i % 256));
+
+	// attempt zero size allocation
+	int const idx2 = a.allocate(0);
+	TEST_CHECK(idx2 == -1);
+
+	// attempt to get a pointer after zero allocation
+	ptr = a.ptr(idx2);
+	TEST_CHECK(ptr == NULL);
 }
 
 TORRENT_TEST(swap)