diff --git a/QGL/Compiler.py b/QGL/Compiler.py
index e3fb8357..21b4ef0d 100644
--- a/QGL/Compiler.py
+++ b/QGL/Compiler.py
@@ -551,7 +551,7 @@ def isZero(self):
 def schedule(channel, pulse, blockLength, alignment):
     '''
     Converts a Pulse or a CompositePulses into an aligned sequence of Pulses
-    by injecting TAPulses before and/or after such that the resulting sequence
+    by injecting Ids before and/or after such that the resulting sequence
     duration is `blockLength`.
         alignment = "left", "right", or "center"
     '''
diff --git a/QGL/PulseSequencer.py b/QGL/PulseSequencer.py
index b0d41d32..28e6a3e4 100644
--- a/QGL/PulseSequencer.py
+++ b/QGL/PulseSequencer.py
@@ -57,6 +57,9 @@ def __init__(self, label, channel, shapeParams, amp=1.0, phase=0, frameChange=0)
         for param in requiredParams:
             if param not in shapeParams.keys():
                 raise NameError("shapeParams must include {0}".format(param))
+        if (self.shapeParams['shapeFun'] == PulseShapes.constant or
+            self.shapeParams['shapeFun'] == PulseShapes.square):
+            self.isTimeAmp = True
 
     def __repr__(self):
         return "Pulse({0}, {1}, {2}, {3}, {4}, {5})".format(
@@ -132,7 +135,6 @@ def TAPulse(label, channel, length, amp, phase=0, frameChange=0):
     '''
     params = {'length': length, 'shapeFun': PulseShapes.constant}
     p = Pulse(label, channel, params, amp, phase, frameChange)
-    p.isTimeAmp = True
     return p
 
 class CompositePulse(object):