diff --git a/artiq/coredevice/ad53xx.py b/artiq/coredevice/ad53xx.py
index 0266ab836..697951343 100644
--- a/artiq/coredevice/ad53xx.py
+++ b/artiq/coredevice/ad53xx.py
@@ -196,7 +196,7 @@ class AD53xx:
             if (ctrl & 0b10000) != 0:
                 # NAC3TODO raise ValueError("DAC over temperature")
                 pass
-            self.core.delay(125.*us)  # NAC3TODO try to restore original 25us after kernel invariants
+            self.core.delay(25.*us)
         self.bus.write(  # enable power and overtemperature shutdown
             (AD53XX_CMD_SPECIAL | AD53XX_SPECIAL_CONTROL | 0b0010) << 8)
         if not blind:
@@ -204,7 +204,7 @@ class AD53xx:
             if (ctrl & 0b10111) != 0b00010:
                 # NAC3TODO raise ValueError("DAC CONTROL readback mismatch")
                 pass
-            self.core.delay(115.*us)  # NAC3TODO try to restore original 15us after kernel invariants
+            self.core.delay(15.*us)
 
     @kernel
     def read_reg(self, channel: int32 = 0, op: int32 = AD53XX_READ_X1A) -> int32:
diff --git a/artiq/coredevice/ad9912.py b/artiq/coredevice/ad9912.py
index 2be434d45..5c294d1de 100644
--- a/artiq/coredevice/ad9912.py
+++ b/artiq/coredevice/ad9912.py
@@ -108,7 +108,7 @@ class AD9912:
         if (prodid != 0x1982) and (prodid != 0x1902):
             # NAC3TODO raise ValueError("Urukul AD9912 product id mismatch")
             pass
-        self.core.delay(300. * us)  # NAC3TODO try to restore 50us after kernel invariants are implemented
+        self.core.delay(50. * us)
         # HSTL power down, CMOS power down
         self.write(AD9912_PWRCNTRL1, 0x80, 1)
         self.cpld.io_update.pulse(2. * us)
diff --git a/artiq/examples/nac3devices/nac3devices.py b/artiq/examples/nac3devices/nac3devices.py
index d6d50fa81..e01313428 100644
--- a/artiq/examples/nac3devices/nac3devices.py
+++ b/artiq/examples/nac3devices/nac3devices.py
@@ -27,23 +27,18 @@ class NAC3Devices(EnvExperiment):
     @kernel
     def run(self):
         self.core.reset()
-        self.core.delay(1.*ms)
         self.zotino0.init()
         self.zotino0.set_leds(0x15)
-        self.core.delay(1.*ms)
         self.zotino0.set_dac([1.2, -5.3, 3.4, 4.5], [0, 1, 2, 3])
 
         self.core.break_realtime()
-        self.core.delay(1.*ms)
         self.mirny0_cpld.init()
         self.mirny0_ch0.init()
         self.mirny0_ch0.set_att_mu(160)
         self.mirny0_ch0.sw.on()
-        self.core.break_realtime()
         self.mirny0_ch0.set_frequency(2500.*MHz)
 
         self.core.break_realtime()
-        self.core.delay(1.*ms)
         self.urukul0_cpld.init()
         self.urukul0_ch0.init()
         self.urukul0_ch0.sw.on()
diff --git a/flake.lock b/flake.lock
index 072ef9421..eeb37f257 100644
--- a/flake.lock
+++ b/flake.lock
@@ -80,11 +80,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1638686158,
-        "narHash": "sha256-x3DSzTZEhpTt2PKIx/HZ+5PuD56ytc6HOZtra/yyInI=",
+        "lastModified": 1638707403,
+        "narHash": "sha256-NcGX9uS5/Gb1geUo4NEZsX5b+Eq9uWkT04iwUVQnHBg=",
         "ref": "master",
-        "rev": "d2919b9620c88756b73aa0cb13f9f014703b67c4",
-        "revCount": 488,
+        "rev": "6d00d4dabb54f6944a9c97981a1d3416093a3df9",
+        "revCount": 490,
         "type": "git",
         "url": "https://git.m-labs.hk/M-Labs/nac3.git"
       },