diff --git a/litex/build/dfu.py b/litex/build/dfu.py
index e9279064f..41caf05d8 100644
--- a/litex/build/dfu.py
+++ b/litex/build/dfu.py
@@ -14,11 +14,18 @@ from litex.build.generic_programmer import GenericProgrammer
 class DFUProg(GenericProgrammer):
     needs_bitreverse = False
 
-    def __init__(self, vid, pid):
+    def __init__(self, vid, pid, alt=None):
         self.vid = vid
         self.pid = pid
+        self.alt = alt
 
-    def load_bitstream(self, bitstream_file):
+    def load_bitstream(self, bitstream_file, reset=True):
         subprocess.call(["cp", bitstream_file, bitstream_file + ".dfu"])
         subprocess.call(["dfu-suffix", "-v", self.vid, "-p", self.pid, "-a", bitstream_file + ".dfu"])
-        subprocess.call(["dfu-util", "--download", bitstream_file + ".dfu", "-R"])
+
+        flash_cmd = ["dfu-util", "--download", bitstream_file + ".dfu"]
+        if reset:
+            flash_cmd.append("-R")
+        if self.alt is not None:
+            flash_cmd.extend(["-a", str(self.alt)])
+        subprocess.call(flash_cmd)