diff --git a/overviewer_core/biome.py b/overviewer_core/biome.py
index 4e20f7f..9910165 100644
--- a/overviewer_core/biome.py
+++ b/overviewer_core/biome.py
@@ -14,31 +14,17 @@
 #    You should have received a copy of the GNU General Public License along
 #    with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
 
-import numpy
 
-class BiomeDispensary:
-    """Turns biome arrays of either 256 or 1024 integer values into 16x16 2d arrays,
-    which can then be retrieved for any Y level with get_biome.
-    """
-    def __init__(self, biome_array):
-        self.biome_len = len(biome_array)
-        if self.biome_len == 256:
-            self.biomes = [biome_array.reshape((16, 16))]
-        elif self.biome_len == 1024:
-            self.biomes = [None] * 16
-            # Each value in the biome array actually stands for 4 blocks, so we take the
-            # Kronecker product of it to "scale" it into its full size of 4096 entries
-            krond = numpy.kron(biome_array, numpy.ones((4)))
-            for i in range(0, 16):
-                # Now we can divide it into 16x16 slices
-                self.biomes[i] = krond[i * 256:(i + 1) * 256].reshape((16, 16))
-
-
-    def get_biome(self, y_level):
-        if self.biome_len == 256 or y_level < 0:
-            return self.biomes[0]
-        else:
-            # We clamp the value to a max of 15 here because apparently Y=16
-            # also exists, and while I don't know what biome level Mojang uses for
-            # that, the highest one is probably a good bet.
-            return self.biomes[min(y_level, 15)]
+def reshape_biome_data(biome_array):
+    biome_len = len(biome_array)
+    if biome_len == 256:
+        return biome_array.reshape((16, 16))
+    elif biome_len == 1024:
+        # Ok here's the big brain explanation:
+        # Minecraft's new biomes have a resolution of 4x4x4 blocks.
+        # This means for a 16x256x16 chunk column we get 64 times for the vertical,
+        # and 4x4 values for the horizontals.
+        # Minecraft Wiki says some dumb thing about how "oh it's ordered by Z, then X, then Y",
+        # but they appear to either be wrong or have explained it with the eloquence of a
+        # caveman.
+        return biome_array.reshape((4, 64, 4))
diff --git a/overviewer_core/src/iterate.c b/overviewer_core/src/iterate.c
index 99a8b3d..f27e400 100644
--- a/overviewer_core/src/iterate.c
+++ b/overviewer_core/src/iterate.c
@@ -109,12 +109,10 @@ static inline void load_chunk_section(ChunkData* dest, int32_t i, PyObject* sect
     dest->sections[i].data = (PyArrayObject*)PyDict_GetItemString(section, "Data");
     dest->sections[i].skylight = (PyArrayObject*)PyDict_GetItemString(section, "SkyLight");
     dest->sections[i].blocklight = (PyArrayObject*)PyDict_GetItemString(section, "BlockLight");
-    dest->sections[i].biomes = (PyArrayObject*)PyDict_GetItemString(section, "Biomes");
     Py_INCREF(dest->sections[i].blocks);
     Py_INCREF(dest->sections[i].data);
     Py_INCREF(dest->sections[i].skylight);
     Py_INCREF(dest->sections[i].blocklight);
-    Py_INCREF(dest->sections[i].biomes);
 }
 
 /* loads the given chunk into the chunks[] array in the state
@@ -132,12 +130,13 @@ bool load_chunk(RenderState* state, int32_t x, int32_t z, uint8_t required) {
     if (dest->loaded)
         return false;
 
+    /* set reasonable defaults */
+    dest->biomes = NULL;
     for (i = 0; i < SECTIONS_PER_CHUNK; i++) {
         dest->sections[i].blocks = NULL;
         dest->sections[i].data = NULL;
         dest->sections[i].skylight = NULL;
         dest->sections[i].blocklight = NULL;
-        dest->sections[i].biomes = NULL;
     }
     dest->loaded = 1;
 
@@ -167,6 +166,9 @@ bool load_chunk(RenderState* state, int32_t x, int32_t z, uint8_t required) {
         return true;
     }
 
+    dest->biomes = (PyArrayObject*)PyDict_GetItemString(chunk, "Biomes");
+    Py_INCREF(dest->biomes);
+    dest->new_biomes = PyObject_IsTrue(PyDict_GetItemString(chunk, "NewBiomes"));
 
     for (i = 0; i < PySequence_Fast_GET_SIZE(sections); i++) {
         PyObject* ycoord = NULL;
@@ -193,12 +195,12 @@ unload_all_chunks(RenderState* state) {
     for (i = 0; i < 3; i++) {
         for (j = 0; j < 3; j++) {
             if (state->chunks[i][j].loaded) {
+                Py_XDECREF(state->chunks[i][j].biomes);
                 for (k = 0; k < SECTIONS_PER_CHUNK; k++) {
                     Py_XDECREF(state->chunks[i][j].sections[k].blocks);
                     Py_XDECREF(state->chunks[i][j].sections[k].data);
                     Py_XDECREF(state->chunks[i][j].sections[k].skylight);
                     Py_XDECREF(state->chunks[i][j].sections[k].blocklight);
-                    Py_XDECREF(state->chunks[i][j].sections[k].biomes);
                 }
                 state->chunks[i][j].loaded = 0;
             }
diff --git a/overviewer_core/src/overviewer.h b/overviewer_core/src/overviewer.h
index 8cac99d..a19688e 100644
--- a/overviewer_core/src/overviewer.h
+++ b/overviewer_core/src/overviewer.h
@@ -29,9 +29,9 @@
 
 #define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 
-// increment this value if you've made a change to the c extesion
+// increment this value if you've made a change to the c extension
 // and want to force users to rebuild
-#define OVERVIEWER_EXTENSION_VERSION 78
+#define OVERVIEWER_EXTENSION_VERSION 79
 
 #include <stdbool.h>
 #include <stdint.h>
@@ -84,10 +84,12 @@ typedef struct {
     int32_t loaded;
     /* chunk biome array */
     PyArrayObject* biomes;
+    /* whether this is a 3d biome array */
+    bool new_biomes;
     /* all the sections in a given chunk */
     struct {
         /* all there is to know about each section */
-        PyArrayObject *blocks, *data, *skylight, *blocklight, *biomes;
+        PyArrayObject *blocks, *data, *skylight, *blocklight;
     } sections[SECTIONS_PER_CHUNK];
 } ChunkData;
 typedef struct {
@@ -210,7 +212,7 @@ static inline uint32_t get_data(RenderState* state, DataType type, int32_t x, in
         data_array = state->chunks[chunkx][chunkz].sections[chunky].skylight;
         break;
     case BIOMES:
-        data_array = state->chunks[chunkx][chunkz].sections[chunky].biomes;
+        data_array = state->chunks[chunkx][chunkz].biomes;
     };
 
     if (data_array == NULL)
@@ -218,8 +220,13 @@ static inline uint32_t get_data(RenderState* state, DataType type, int32_t x, in
 
     if (type == BLOCKS)
         return getArrayShort3D(data_array, x, y, z);
-    if (type == BIOMES)
-        return getArrayByte2D(data_array, x, z);
+    if (type == BIOMES) {
+        if (state->chunks[chunkx][chunkz].new_biomes) {
+            return getArrayByte3D(data_array, x / 4, y / 4, z / 4);
+        } else {
+            return getArrayByte2D(data_array, x, z);
+        }
+    }
     return getArrayByte3D(data_array, x, y, z);
 }
 
diff --git a/overviewer_core/world.py b/overviewer_core/world.py
index 2768843..691c1df 100644
--- a/overviewer_core/world.py
+++ b/overviewer_core/world.py
@@ -26,7 +26,7 @@ import numpy
 
 from . import nbt
 from . import cache
-from .biome import BiomeDispensary
+from .biome import reshape_biome_data
 
 """
 This module has routines for extracting information about available worlds
@@ -1372,15 +1372,14 @@ class RegionSet(object):
                 biomes = numpy.frombuffer(biomes, dtype=numpy.uint8)
             else:
                 biomes = numpy.asarray(biomes)
-            #biomes = biomes.reshape((16,16))
-            biome_giver = BiomeDispensary(biomes)
+            biomes = reshape_biome_data(biomes)
         else:
             # Worlds converted by Jeb's program may be missing the Biomes key.
             # Additionally, 19w09a worlds have an empty array as biomes key
             # in some cases.
-            #biomes = numpy.zeros((16, 16), dtype=numpy.uint8)
-            biome_giver = BiomeDispensary(numpy.zeros(256, dtype=numpy.uint8))
-        #chunk_data['Biomes'] = biomes
+            biomes = numpy.zeros((16, 16), dtype=numpy.uint8)
+        chunk_data['Biomes'] = biomes
+        chunk_data['NewBiomes'] = (len(biomes.shape) == 3)
 
         unrecognized_block_types = {}
         for section in chunk_data['Sections']:
@@ -1388,7 +1387,6 @@ class RegionSet(object):
             # Turn the skylight array into a 16x16x16 matrix. The array comes
             # packed 2 elements per byte, so we need to expand it.
             try:
-                section['Biomes'] = biome_giver.get_biome(section["Y"])
                 if 'SkyLight' in section:
                     skylight = numpy.frombuffer(section['SkyLight'], dtype=numpy.uint8)
                     skylight = skylight.reshape((16,16,8))
@@ -1612,9 +1610,6 @@ class RotatedRegionSet(RegionSetWrapper):
         for section in chunk_data['Sections']:
             section = dict(section)
             newsections.append(section)
-            biomes = numpy.swapaxes(section['Biomes'], 0, 1)
-            biomes = numpy.rot90(biomes, self.north_dir)
-            section['Biomes'] = numpy.swapaxes(biomes, 0, 1)
             for arrayname in ['Blocks', 'Data', 'SkyLight', 'BlockLight']:
                 array = section[arrayname]
                 # Since the anvil change, arrays are arranged with axes Y,Z,X
@@ -1626,7 +1621,15 @@ class RotatedRegionSet(RegionSetWrapper):
                 section[arrayname] = array
         chunk_data['Sections'] = newsections
 
-        # same as above, for biomes (Z/X indexed)
+        if chunk_data['NewBiomes']:
+            array = numpy.swapaxes(chunk_data['Biomes'], 0, 2)
+            array = numpy.rot90(array, self.north_dir)
+            chunk_data['Biomes'] = numpy.swapaxes(array, 0, 2)
+        else:
+            # same as above, for biomes (Z/X indexed)
+            biomes = numpy.swapaxes(chunk_data['Biomes'], 0, 1)
+            biomes = numpy.rot90(biomes, self.north_dir)
+            chunk_data['Biomes'] = numpy.swapaxes(biomes, 0, 1)
         return chunk_data
 
     def get_chunk_mtime(self, x, z):