diff --git a/dtool/src/dtoolbase/memoryHook.I b/dtool/src/dtoolbase/memoryHook.I
index 989652d884..b3a9501ad5 100644
--- a/dtool/src/dtoolbase/memoryHook.I
+++ b/dtool/src/dtoolbase/memoryHook.I
@@ -136,11 +136,11 @@ alloc_to_ptr(void *alloc, size_t size) {
 #if defined(MEMORY_HOOK_DO_ALIGN)
   size_t alignment = get_memory_alignment();
   // Move the allocated pointer up to the next even alignment.
-  void *new_ptr = (void *)((((size_t)alloc + alignment - 1) / alignment) * alignment);
-  size_t *root = (size_t *)new_ptr;
+  size_t *root = (size_t *)((((size_t)alloc + alignment - 1) / alignment) * alignment);
+  assert(alloc <= root && (char *)root - (char *)alloc < alignment);
   root[0] = size;
   root[1] = (size_t)alloc;  // Save the pointer we originally allocated.
-  return (void *)((char *)new_ptr + _header_reserved_bytes);
+  return (void *)((char *)root + _header_reserved_bytes);
 #elif defined(DO_MEMORY_USAGE) 
   size_t *root = (size_t *)alloc;
   root[0] = size;
@@ -162,7 +162,9 @@ ptr_to_alloc(void *ptr, size_t &size) {
 #if defined(MEMORY_HOOK_DO_ALIGN)
   size_t *root = (size_t *)((char *)ptr - _header_reserved_bytes);
   size = root[0];
-  return (void *)root[1];  // Return the pointer we originally allocated.
+  void *alloc = (void *)root[1]; // Get the pointer we originally allocated.
+  assert(alloc <= root && (char *)root - (char *)alloc < get_memory_alignment());
+  return alloc;
 #elif defined(DO_MEMORY_USAGE) 
   size_t *root = (size_t *)((char *)ptr - _header_reserved_bytes);
   size = root[0];
diff --git a/dtool/src/dtoolbase/memoryHook.cxx b/dtool/src/dtoolbase/memoryHook.cxx
index aefc849ddc..618a0e0d33 100644
--- a/dtool/src/dtoolbase/memoryHook.cxx
+++ b/dtool/src/dtoolbase/memoryHook.cxx
@@ -224,7 +224,9 @@ heap_alloc_single(size_t size) {
   }
 #endif  // DO_MEMORY_USAGE
 
-  return alloc_to_ptr(alloc, size);
+  void *ptr = alloc_to_ptr(alloc, size);
+  assert(ptr >= alloc && (char *)ptr + size <= (char *)alloc + inflated_size);
+  return ptr;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -298,7 +300,9 @@ heap_alloc_array(size_t size) {
   }
 #endif  // DO_MEMORY_USAGE
 
-  return alloc_to_ptr(alloc, size);
+  void *ptr = alloc_to_ptr(alloc, size);
+  assert(ptr >= alloc && (char *)ptr + size <= (char *)alloc + inflated_size);
+  return ptr;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -319,30 +323,42 @@ heap_realloc_array(void *ptr, size_t size) {
 
   size_t inflated_size = inflate_size(size);
 
+  void *alloc1 = alloc;
 #ifdef MEMORY_HOOK_MALLOC_LOCK
   _lock.acquire();
-  alloc = call_realloc(alloc, inflated_size);
+  alloc1 = call_realloc(alloc1, inflated_size);
   _lock.release();
 #else
-  alloc = call_realloc(alloc, inflated_size);
+  alloc1 = call_realloc(alloc1, inflated_size);
 #endif
 
-  while (alloc == (void *)NULL) {
+  while (alloc1 == (void *)NULL) {
     alloc_fail(inflated_size);
     
     // Recover the original pointer.
-    alloc = ptr_to_alloc(ptr, orig_size);
+    alloc1 = alloc;
 
 #ifdef MEMORY_HOOK_MALLOC_LOCK
     _lock.acquire();
-    alloc = call_realloc(alloc, inflated_size);
+    alloc1 = call_realloc(alloc1, inflated_size);
     _lock.release();
 #else
-    alloc = call_realloc(alloc, inflated_size);
+    alloc1 = call_realloc(alloc1, inflated_size);
 #endif
   }
 
-  return alloc_to_ptr(alloc, size);
+  void *ptr1 = alloc_to_ptr(alloc1, size);
+  assert(ptr1 >= alloc1 && (char *)ptr1 + size <= (char *)alloc1 + inflated_size);
+#if defined(MEMORY_HOOK_DO_ALIGN)
+  // We might have to shift the memory to account for the new offset
+  // due to the alignment.
+  size_t orig_delta = (char *)ptr - (char *)alloc;
+  size_t new_delta = (char *)ptr1 - (char *)alloc1;
+  if (orig_delta != new_delta) {
+    memmove((char *)alloc1 + new_delta, (char *)alloc1 + orig_delta, min(size, orig_size));
+  }
+#endif  // MEMORY_HOOK_DO_ALIGN
+  return ptr1;
 }
 
 ////////////////////////////////////////////////////////////////////
diff --git a/panda/src/gobj/geomVertexColumn.h b/panda/src/gobj/geomVertexColumn.h
index df986ee99d..1794ab3d9a 100644
--- a/panda/src/gobj/geomVertexColumn.h
+++ b/panda/src/gobj/geomVertexColumn.h
@@ -102,7 +102,7 @@ private:
   // for implementing the common, very direct code paths (for
   // instance, 3-component float32 to LVecBase3f) as quickly as
   // possible.
-  class Packer {
+  class Packer : public MemoryBase {
   public:
     virtual ~Packer();
 
diff --git a/panda/src/text/textAssembler.h b/panda/src/text/textAssembler.h
index 772fcf0f9f..07bb80b0b9 100644
--- a/panda/src/text/textAssembler.h
+++ b/panda/src/text/textAssembler.h
@@ -218,7 +218,7 @@ private:
   };
   typedef pmap<GeomCollectorKey, GeomCollector> GeomCollectorMap;
 
-  class GlyphPlacement {
+  class GlyphPlacement : public MemoryBase {
   public:
     INLINE void add_piece(Geom *geom, const RenderState *state);
     void calc_tight_bounds(LPoint3 &min_point, LPoint3 &max_point,