diff --git a/artiq/language/core.py b/artiq/language/core.py
index e607521a3..79ab87a89 100644
--- a/artiq/language/core.py
+++ b/artiq/language/core.py
@@ -330,8 +330,6 @@ def syscall(*args):
 
 _encoded_exceptions = dict()
 
-first_user_eid = 1024
-
 
 def EncodedException(eid):
     """Represents exceptions on the core device, which are identified
@@ -346,3 +344,6 @@ def EncodedException(eid):
                 Exception.__init__(self, eid)
         _encoded_exceptions[eid] = EncodedException
         return EncodedException
+
+
+first_user_eid = 1024
diff --git a/artiq/transforms/lower_units.py b/artiq/transforms/lower_units.py
index 16017a372..9b79c839e 100644
--- a/artiq/transforms/lower_units.py
+++ b/artiq/transforms/lower_units.py
@@ -1,7 +1,6 @@
 import ast
 
 from artiq.transforms.tools import value_to_ast
-from artiq.language import units
 
 
 # TODO:
@@ -41,7 +40,4 @@ class _UnitsLowerer(ast.NodeTransformer):
 
 
 def lower_units(func_def, ref_period):
-    if (not isinstance(ref_period, units.Quantity)
-            or ref_period.unit is not units.s_unit):
-        raise units.DimensionError("Reference period not expressed in seconds")
     _UnitsLowerer(ref_period.amount).visit(func_def)
diff --git a/test/full_stack.py b/test/full_stack.py
index 05392eb30..744e55292 100644
--- a/test/full_stack.py
+++ b/test/full_stack.py
@@ -105,7 +105,7 @@ class _RTIOUnderflow(AutoContext):
 
     @kernel
     def run(self):
-        for i in range(10000):
+        while True:
             delay(25*ns)
             self.o.pulse(25*ns)
 
diff --git a/test/py2llvm.py b/test/py2llvm.py
index 4f9465f39..b957032a5 100644
--- a/test/py2llvm.py
+++ b/test/py2llvm.py
@@ -205,8 +205,8 @@ def _test_range():
 class CodeGenCase(unittest.TestCase):
     def _test_float_arith(self, op):
         arith_c = CompiledFunction(arith, {
-                "op": base_types.VInt(),
-                "a": base_types.VFloat(), "b": base_types.VFloat()})
+            "op": base_types.VInt(),
+            "a": base_types.VFloat(), "b": base_types.VFloat()})
         for a in _test_range():
             for b in _test_range():
                 self.assertEqual(arith_c(op, a/2, b/2), arith(op, a/2, b/2))