diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b8d6af6c0..bece205c1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -44,7 +44,8 @@ The format is based on [Keep a Changelog].
 -   ZYZ decomposition for single-qubit unitaries (\#2600)
 
 ### Changed
--   Pulse commands may now start with capitalized letters. 
+-   Set default repetition time to be the first available.
+-   Pulse commands may now start with capitalized letters.
 -   The `pylatexenc` and `pillow` requirements are now optional. These
     are only used by the `latex` and `latex_source` circuit
     visualization backends. To continue using them ensure these are
diff --git a/qiskit/compiler/assemble.py b/qiskit/compiler/assemble.py
index 0bd530b303..51ec553747 100644
--- a/qiskit/compiler/assemble.py
+++ b/qiskit/compiler/assemble.py
@@ -201,7 +201,7 @@ def _parse_run_args(backend, qobj_id, qobj_header,
     memory_slots = memory_slots or getattr(backend_config, 'memory_slots', None)
     rep_time = rep_time or getattr(backend_config, 'rep_times', None)
     if isinstance(rep_time, list):
-        rep_time = rep_time[-1]
+        rep_time = rep_time[0]
 
     parameter_binds = parameter_binds or []