diff --git a/NEWS b/NEWS
index 5c044ef2ac9..65f08921922 100644
--- a/NEWS
+++ b/NEWS
@@ -546,7 +546,8 @@ PHP                                                                        NEWS
     (Pierre)
   . Fixed bug #72482 (Ilegal write/read access caused by gdImageAALine
     overflow). (Pierre)
-  . Fixed bug #72494 (imagecropauto out-of-bounds access). (Pierre)
+  . Fixed bug #72494 (imagecropauto out-of-bounds access). (Fernando, Pierre,
+    cmb)
 
 - Intl:
   . Partially fixed #72506 (idn_to_ascii for UTS #46 incorrect for long domain
diff --git a/ext/gd/libgd/gd_crop.c b/ext/gd/libgd/gd_crop.c
index 83315214465..58b630317dd 100644
--- a/ext/gd/libgd/gd_crop.c
+++ b/ext/gd/libgd/gd_crop.c
@@ -243,6 +243,10 @@ gdImagePtr gdImageCropThreshold(gdImagePtr im, const unsigned int color, const f
 		return NULL;
 	}
 
+	if (!gdImageTrueColor(im) && color >= gdImageColorsTotal(im)) {
+		return NULL;
+	}
+
 	/* TODO: Add gdImageGetRowPtr and works with ptr at the row level
 	 * for the true color and palette images
 	 * new formats will simply work with ptr
diff --git a/ext/gd/tests/bug72494.phpt b/ext/gd/tests/bug72494.phpt
new file mode 100644
index 00000000000..f21de6ca3b8
--- /dev/null
+++ b/ext/gd/tests/bug72494.phpt
@@ -0,0 +1,15 @@
+--TEST--
+Bug #72494 (imagecropauto out-of-bounds access)
+--SKIPIF--
+<?php
+if (!extension_loaded('gd')) die('skip gd extension not available');
+?>
+--FILE--
+<?php
+$im = imagecreate(10,10);
+imagecropauto($im, IMG_CROP_THRESHOLD, 0, 1337);
+?>
+===DONE===
+--EXPECTF--
+Warning: imagecropauto(): Color argument missing with threshold mode in %s on line %d
+===DONE===