diff --git a/artiq/gateware/targets/pipistrello.py b/artiq/gateware/targets/pipistrello.py
index 2b2c7de65..6a6d1366d 100755
--- a/artiq/gateware/targets/pipistrello.py
+++ b/artiq/gateware/targets/pipistrello.py
@@ -147,6 +147,7 @@ class NIST_QC1(BaseSoC, AMPSoC):
                          l2_size=64*1024,
                          with_timer=False,
                          ident=artiq_version,
+                         clk_freq=75*1000*1000,
                          **kwargs)
         AMPSoC.__init__(self)