diff --git a/artiq/coredevice/ad9910.py b/artiq/coredevice/ad9910.py
index 44cd621a4..1065517df 100644
--- a/artiq/coredevice/ad9910.py
+++ b/artiq/coredevice/ad9910.py
@@ -603,7 +603,7 @@ class AD9910:
         """
         for i in range(len(ram)):
             ram[i] = ((self.turns_to_pow(turns[i]) << 16) |
-                      self.amplitude_to_asf(amplitude[i]))
+                      self.amplitude_to_asf(amplitude[i]) << 2)
 
     @kernel
     def set_frequency(self, frequency):