diff --git a/Tests/helper.py b/Tests/helper.py
index be3bdb76f..5573c78c4 100644
--- a/Tests/helper.py
+++ b/Tests/helper.py
@@ -257,8 +257,16 @@ def netpbm_available():
     return bool(shutil.which("ppmquant") and shutil.which("ppmtogif"))
 
 
+def convert_available():
+    return imagemagick_available() or graphicsmagick_available()
+
+
 def imagemagick_available():
-    return bool(IMCONVERT and shutil.which(IMCONVERT))
+    return bool(IMCONVERT and shutil.which(IMCONVERT[0]))
+
+
+def graphicsmagick_available():
+    return bool(GMCONVERT and shutil.which(GMCONVERT[0]))
 
 
 def on_appveyor():
@@ -298,10 +306,20 @@ def is_mingw():
 
 if sys.platform == "win32":
     IMCONVERT = os.environ.get("MAGICK_HOME", "")
+    GMCONVERT = None
     if IMCONVERT:
-        IMCONVERT = os.path.join(IMCONVERT, "convert.exe")
+        IMCONVERT = [os.path.join(IMCONVERT, "convert.exe")]
+        GMCONVERT = [os.path.join(IMCONVERT, "gm.exe"), "convert"]
 else:
-    IMCONVERT = "convert"
+    IMCONVERT = ["convert"]
+    GMCONVERT = ["gm", "convert"]
+
+if imagemagick_available():
+    CONVERT = IMCONVERT
+elif graphicsmagick_available():
+    CONVERT = GMCONVERT
+else:
+    CONVERT = None
 
 
 class cached_property:
diff --git a/Tests/test_file_palm.py b/Tests/test_file_palm.py
index 25d194b62..bbbab25d8 100644
--- a/Tests/test_file_palm.py
+++ b/Tests/test_file_palm.py
@@ -5,9 +5,9 @@ import pytest
 
 from PIL import Image
 
-from .helper import IMCONVERT, assert_image_equal, hopper, imagemagick_available
+from .helper import CONVERT, assert_image_equal, convert_available, hopper
 
-_roundtrip = imagemagick_available()
+_roundtrip = convert_available()
 
 
 def helper_save_as_palm(tmp_path, mode):
@@ -23,13 +23,13 @@ def helper_save_as_palm(tmp_path, mode):
     assert os.path.getsize(outfile) > 0
 
 
-def open_with_imagemagick(tmp_path, f):
-    if not imagemagick_available():
+def open_with_convert(tmp_path, f):
+    if not convert_available():
         raise OSError()
 
     outfile = str(tmp_path / "temp.png")
     rc = subprocess.call(
-        [IMCONVERT, f, outfile], stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT
+        CONVERT + [f, outfile], stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT
     )
     if rc:
         raise OSError
@@ -44,7 +44,7 @@ def roundtrip(tmp_path, mode):
     outfile = str(tmp_path / "temp.palm")
 
     im.save(outfile)
-    converted = open_with_imagemagick(tmp_path, outfile)
+    converted = open_with_convert(tmp_path, outfile)
     assert_image_equal(converted, im)