diff --git a/PIL/Image.py b/PIL/Image.py
index e71e2ad5f..442393a9e 100644
--- a/PIL/Image.py
+++ b/PIL/Image.py
@@ -734,7 +734,10 @@ class Image:
 
         if mode == "P" and palette == ADAPTIVE:
             im = self.im.quantize(colors)
-            return self._new(im)
+            new = self._new(im)
+            from PIL import ImagePalette
+            new.palette = ImagePalette.raw("RGB", new.im.getpalette("RGB"))
+            return new
 
         # colorspace conversion
         if dither is None:
diff --git a/PIL/PngImagePlugin.py b/PIL/PngImagePlugin.py
index 30fdfb8ac..d72a9c141 100644
--- a/PIL/PngImagePlugin.py
+++ b/PIL/PngImagePlugin.py
@@ -505,7 +505,7 @@ def _save(im, fp, filename, chunk=putchunk, check=0):
         else:
             # check palette contents
             if im.palette:
-                colors = max(len(im.im.getpalette("RGB"))//3, 256)
+                colors = max(min(len(im.palette.getdata()[1])//3, 256), 2)
             else:
                 colors = 256