diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 45deacd4..04d2ab55 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -144,7 +144,7 @@ jobs:
           key:
             ${{ runner.os }}-conda-${{ matrix.python-version }}-${{ hashFiles('environment.yml') }}
 
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           python-version: ${{ matrix.python-version }}
           environment-file: environment.yml
diff --git a/terracotta/cmaps/generate_cmaps.py b/terracotta/cmaps/generate_cmaps.py
index b5ad4992..8556f2ad 100644
--- a/terracotta/cmaps/generate_cmaps.py
+++ b/terracotta/cmaps/generate_cmaps.py
@@ -4,12 +4,11 @@
 """
 
 import numpy as np
-import matplotlib.cm as cm
+import matplotlib as mpl
 
 from terracotta.cmaps.get_cmaps import SUFFIX
 
-ALL_CMAPS = list(cm.cmaps_listed) + list(cm.datad)
-ALL_CMAPS.extend([f"{cmap}_r" for cmap in ALL_CMAPS])
+ALL_CMAPS = list(mpl.colormaps)
 NUM_VALS = 255
 
 
@@ -17,7 +16,7 @@ def generate_maps(out_folder: str) -> None:
     x = np.linspace(0, 1, NUM_VALS)
     for cmap in ALL_CMAPS:
         print(cmap)
-        cmap_fun = cm.get_cmap(cmap)
+        cmap_fun = mpl.colormaps[cmap]
         cmap_vals = cmap_fun(x)
         cmap_uint8 = (cmap_vals * 255).astype("uint8")
         np.save(f"{out_folder}/{cmap.lower()}{SUFFIX}", cmap_uint8)
diff --git a/terracotta/scripts/optimize_rasters.py b/terracotta/scripts/optimize_rasters.py
index 32c7e707..70a4876e 100644
--- a/terracotta/scripts/optimize_rasters.py
+++ b/terracotta/scripts/optimize_rasters.py
@@ -32,7 +32,7 @@
 
 IN_MEMORY_THRESHOLD = 10980 * 10980
 
-CACHEMAX = 1024 * 1024 * 512  # 512 MB
+CACHEMAX = os.environ.get("GDAL_CACHEMAX", 1024 * 1024 * 512)  # 512 MB
 
 GDAL_CONFIG = {
     "GDAL_TIFF_INTERNAL_MASK": True,