diff --git a/CHANGELOG b/CHANGELOG
index 9727820..f6609a2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,9 @@
  * CHANGELOG.
  */
 
+09062005 - Happy September. Changed the allocation abstraction to use
+           PHYSFS_uint64 instead of size_t, so we don't have to include
+           system headers inside physfs.h.
 08202005 - Fixed bug in verifyPath() that was breaking PHYSFS_setSaneConfig()
            and other corner cases.
 07242005 - Patched to compile on BeOS.
diff --git a/physfs.h b/physfs.h
index c6b51cd..8557f1f 100644
--- a/physfs.h
+++ b/physfs.h
@@ -1857,14 +1857,21 @@ __EXPORT__ int PHYSFS_writeUBE64(PHYSFS_File *file, PHYSFS_uint64 val);
  *  Allocators are assumed to be reentrant by the caller; please mutex
  *  accordingly.
  *
+ * Allocations are always discussed in 64-bits, for future expansion...we're
+ *  on the cusp of a 64-bit transition, and we'll probably be allocating 6
+ *  gigabytes like it's nothing sooner or later, and I don't want to change
+ *  this again at that point. If you're on a 32-bit platform and have to
+ *  downcast, it's okay to return NULL if the allocation is greater than
+ *  4 gigabytes, since you'd have to do so anyhow.
+ *
  * \sa PHYSFS_setAllocator
  */
 typedef struct
 {
     int (*Init)(void);
     void (*Deinit)(void);
-    void *(*Malloc)(size_t);
-    void *(*Realloc)(void *, size_t);
+    void *(*Malloc)(PHYSFS_uint64);
+    void *(*Realloc)(void *, PHYSFS_uint64);
     void (*Free)(void *);
 } PHYSFS_Allocator;
 
diff --git a/physfs_internal.h b/physfs_internal.h
index 41e1224..dc70205 100644
--- a/physfs_internal.h
+++ b/physfs_internal.h
@@ -1682,14 +1682,14 @@ void __PHYSFS_platformAllocatorDeinit(void);
  *  This is used for allocation if the user hasn't selected their own
  *  allocator via PHYSFS_setAllocator().
  */
-void *__PHYSFS_platformAllocatorMalloc(size_t s);
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s);
 
 /*
  * Implement realloc. It's safe to just pass through from the C runtime.
  *  This is used for allocation if the user hasn't selected their own
  *  allocator via PHYSFS_setAllocator().
  */
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s);
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s);
 
 /*
  * Implement free. It's safe to just pass through from the C runtime.
diff --git a/platform/macclassic.c b/platform/macclassic.c
index f1841a9..3470805 100644
--- a/platform/macclassic.c
+++ b/platform/macclassic.c
@@ -939,17 +939,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */
 
 
diff --git a/platform/os2.c b/platform/os2.c
index 31d9f11..58f635a 100644
--- a/platform/os2.c
+++ b/platform/os2.c
@@ -754,17 +754,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */
 
 
diff --git a/platform/pocketpc.c b/platform/pocketpc.c
index f5b7cf1..0284ab0 100644
--- a/platform/pocketpc.c
+++ b/platform/pocketpc.c
@@ -672,17 +672,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */
 
 
diff --git a/platform/posix.c b/platform/posix.c
index 9e4a6dc..dc9cbad 100644
--- a/platform/posix.c
+++ b/platform/posix.c
@@ -514,17 +514,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */
 
 
diff --git a/platform/skeleton.c b/platform/skeleton.c
index 7aaab69..372aa35 100644
--- a/platform/skeleton.c
+++ b/platform/skeleton.c
@@ -246,17 +246,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */
 
 
diff --git a/platform/win32.c b/platform/win32.c
index c80e5c0..31bfd0c 100644
--- a/platform/win32.c
+++ b/platform/win32.c
@@ -1122,17 +1122,23 @@ void __PHYSFS_platformAllocatorDeinit(void)
 } /* __PHYSFS_platformAllocatorInit */
 
 
-void *__PHYSFS_platformAllocatorMalloc(size_t s)
+void *__PHYSFS_platformAllocatorMalloc(PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef malloc
-    return(malloc(s));
+    return(malloc((size_t) s));
 } /* __PHYSFS_platformMalloc */
 
 
-void *__PHYSFS_platformAllocatorRealloc(void *ptr, size_t s)
+void *__PHYSFS_platformAllocatorRealloc(void *ptr, PHYSFS_uint64 s)
 {
+    /* make sure s isn't larger than the address space of the platform... */
+    if ( s > (0xFFFFFFFFFFFFFFFF >> (64-(sizeof (size_t) * 8))) )
+        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
     #undef realloc
-    return(realloc(ptr, s));
+    return(realloc(ptr, (size_t) s));
 } /* __PHYSFS_platformRealloc */