diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..55d37d2
Binary files /dev/null and b/.DS_Store differ
diff --git a/miniwob/screenshot.py b/miniwob/screenshot.py
index 9fe6f9b..f333fac 100644
--- a/miniwob/screenshot.py
+++ b/miniwob/screenshot.py
@@ -41,7 +41,13 @@ def get_screenshot(
     if icc_profile:
         orig_icc = ImageCms.ImageCmsProfile(BytesIO(icc_profile))
         srgb_icc = ImageCms.createProfile("sRGB")
-        pil_image = ImageCms.profileToProfile(pil_image, orig_icc, srgb_icc)
+        pil_image = ImageCms.profileToProfile(
+            pil_image, orig_icc, srgb_icc, inPlace=False
+        )
+
+    if pil_image is None:
+        raise ValueError("profileToProfile returned None unexpectedly")
+
     return pil_image
 
 
diff --git a/pyproject.toml b/pyproject.toml
index cc69139..52c2623 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
 ]
 dependencies = [
-    "Gymnasium>=1.0.0a1",
+    "Gymnasium>=1.0.0",
     "Pillow>=9.0.0",
     "selenium>=4.5.0",
     "numpy>=1.18.0",