diff --git a/src/gd_crop.c b/src/gd_crop.c
index 02966336d..532b49b3b 100644
--- a/src/gd_crop.c
+++ b/src/gd_crop.c
@@ -136,6 +136,10 @@ BGD_DECLARE(gdImagePtr) gdImageCropThreshold(gdImagePtr im, const unsigned int c
 		return NULL;
 	}
 
+	if (color < 0 || (!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/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 6f5c78604..5093d526a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -31,6 +31,7 @@ if (BUILD_TEST)
 		gdimagecolortransparent
 		gdimagecopy
 		gdimagecopyrotated
+        gdimagecrop
 		gdimagefile
 		gdimagefill
 		gdimagefilledellipse
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4f6e75699..5a0ebe81e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -25,6 +25,7 @@ include gdimagecolorresolve/Makemodule.am
 include gdimagecolortransparent/Makemodule.am
 include gdimagecopy/Makemodule.am
 include gdimagecopyrotated/Makemodule.am
+include gdimagecrop/Makemodule.am
 include gdimagefile/Makemodule.am
 include gdimagefill/Makemodule.am
 include gdimagefilledellipse/Makemodule.am