@@ -5,7 +5,12 @@
 
 from PIL import Image, ImageMorph, _imagingmorph
 
-from .helper import assert_image_equal_tofile, hopper, timeout_unless_slower_valgrind
+from .helper import (
+    assert_image_equal,
+    assert_image_equal_tofile,
+    hopper,
+    timeout_unless_slower_valgrind,
+)
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
@@ -85,6 +90,13 @@ def test_no_operator_loaded() -> None:
         mop.save_lut("")
 
 
+def test_zero_width() -> None:
+    im = Image.new("L", (0, 1))
+    mop = ImageMorph.MorphOp(op_name="erosion8")
+    count, out = mop.apply(im)
+    assert_image_equal(im, out)
+
+
 # Test the named patterns
 def test_erosion8() -> None:
     # erosion8
 
@@ -62,6 +62,9 @@ apply(PyObject *self, PyObject *args) {
     }
     width = imgin->xsize;
     height = imgin->ysize;
+    if (!width || !height) {
+        return Py_BuildValue("i", num_changed_pixels);
+    }
 
     if (imgin->type != IMAGING_TYPE_UINT8 || imgin->bands != 1 ||
         imgout->type != IMAGING_TYPE_UINT8 || imgout->bands != 1) {
Original file line number	Diff line number	Diff line change
`@@ -62,6 +62,9 @@ apply(PyObject self, PyObject args) {`
`62`	`62`	`}`
`63`	`63`	`width = imgin->xsize;`
`64`	`64`	`height = imgin->ysize;`
	`65`	`+ if (!width \|\| !height) {`
	`66`	`+ return Py_BuildValue("i", num_changed_pixels);`
	`67`	`+ }`
`65`	`68`
`66`	`69`	`if (imgin->type != IMAGING_TYPE_UINT8 \|\| imgin->bands != 1 \|\|`
`67`	`70`	`imgout->type != IMAGING_TYPE_UINT8 \|\| imgout->bands != 1) {`