diff --git a/activitysim/abm/test/test_pipeline.py b/activitysim/abm/test/test_pipeline.py
index 1ad0a002d..fb2fe15a0 100644
--- a/activitysim/abm/test/test_pipeline.py
+++ b/activitysim/abm/test/test_pipeline.py
@@ -68,7 +68,7 @@ def close_handlers():
 def inject_settings(configs_dir, **kwargs):
 
     with open(os.path.join(configs_dir, 'settings.yaml')) as f:
-        settings = yaml.load(f)
+        settings = yaml.load(f, Loader=yaml.SafeLoader)
 
         for k in kwargs:
             settings[k] = kwargs[k]
diff --git a/activitysim/core/config.py b/activitysim/core/config.py
index 73d7ae001..07b27f398 100644
--- a/activitysim/core/config.py
+++ b/activitysim/core/config.py
@@ -343,11 +343,9 @@ def backfill_settings(settings, backfill):
                 logger.warn("read settings for %s from %s" % (file_name, file_path))
 
             with open(file_path) as f:
-                s = yaml.load(f)
+                s = yaml.load(f, Loader=yaml.SafeLoader)
             settings = backfill_settings(settings, s)
 
-            print("settings after %s\n%s\n\n" % (file_path, settings))
-
             if s.get('inherit_settings', False):
                 logger.warn("inherit_settings flag set for %s in %s" % (file_name, file_path))
                 continue
diff --git a/activitysim/core/mp_tasks.py b/activitysim/core/mp_tasks.py
index 887854a06..54fc6f9be 100644
--- a/activitysim/core/mp_tasks.py
+++ b/activitysim/core/mp_tasks.py
@@ -1524,7 +1524,7 @@ def read_breadcrumbs():
     if not os.path.exists(file_path):
         raise IOError("Could not find saved breadcrumbs file '%s'" % file_path)
     with open(file_path, 'r') as f:
-        breadcrumbs = yaml.load(f)
+        breadcrumbs = yaml.load(f, Loader=yaml.SafeLoader)
     # convert array to ordered dict keyed by step name
     breadcrumbs = OrderedDict([(step['name'], step) for step in breadcrumbs])
     return breadcrumbs
diff --git a/activitysim/core/tracing.py b/activitysim/core/tracing.py
index a915c16c5..027881f81 100644
--- a/activitysim/core/tracing.py
+++ b/activitysim/core/tracing.py
@@ -129,7 +129,8 @@ def config_logger(basic=False):
 
     if log_config_file:
         with open(log_config_file) as f:
-            config_dict = yaml.load(f)
+            # FIXME need alternative to yaml.UnsafeLoader?
+            config_dict = yaml.load(f, Loader=yaml.UnsafeLoader)
             config_dict = config_dict['logging']
             config_dict.setdefault('version', 1)
             logging.config.dictConfig(config_dict)
diff --git a/setup.py b/setup.py
index 527d9fbe3..5d0d7b757 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
         'numpy == 1.15.4',  # https://github.com/PyTables/PyTables/issues/719
         'openmatrix >= 0.3.4.1',
         'pandas >= 0.20.3',
-        'pyyaml >= 3.0, <5.1',
+        'pyyaml >= 3.0',
         'tables >= 3.3.0',
         'toolz >= 0.8.1',
         'zbox >= 1.2',