diff --git a/Default/mappings.py b/Default/mappings.py
index 973d96fe..dcbac0ae 100644
--- a/Default/mappings.py
+++ b/Default/mappings.py
@@ -5,7 +5,7 @@
 # Which class names to map to resources and elements
 classmap = {
     'Any': 'Resource',
-    'Practitioner.role': 'PractRole',   # to avoid Practinioner.role and PractitionerRole generating the same class
+    'Practitioner.role': 'PractRole',   # to avoid Practitioner.role and PractitionerRole generating the same class
     
     'boolean': 'bool',
     'integer': 'int',
diff --git a/README.md b/README.md
index ba7dcdc5..3ab80a8e 100644
--- a/README.md
+++ b/README.md
@@ -8,9 +8,7 @@ If you've come here because you want _Swift_ or _Python_ classes for FHIR data m
 - [Swift-FHIR][] and [Swift-SMART][]
 - Python [client-py][]
 
-The `master` branch is currently capable of parsing _STU 3, v3.0.0_.  
-The `develop` branch should be capable of parsing the continuous integration build and will be merged into master on new major FHIR releases.
-There may be tags for specific freezes, see [releases](https://github.com/smart-on-fhir/fhir-parser/releases).
+The `master` branch is currently capable of parsing _R5_.
 
 This work is licensed under the [APACHE license][license].
 FHIR® is the registered trademark of [HL7][] and is used with the permission of HL7.
diff --git a/fhirrenderer.py b/fhirrenderer.py
index 5c735734..77e66c6b 100644
--- a/fhirrenderer.py
+++ b/fhirrenderer.py
@@ -8,7 +8,7 @@
 import textwrap
 
 from jinja2 import Environment, PackageLoader, TemplateNotFound
-from jinja2.filters import environmentfilter
+from jinja2.filters import pass_environment
 from logger import logger
 
 
@@ -202,7 +202,7 @@ def render(self):
 # ignores existing linebreaks when applying the wrap:
 # https://github.com/mitsuhiko/jinja2/issues/175
 # Here's the workaround:
-@environmentfilter
+@pass_environment
 def do_wordwrap(environment, s, width=79, break_long_words=True, wrapstring=None):
     """
     Return a copy of the string passed to the filter wrapped after
@@ -211,7 +211,7 @@ def do_wordwrap(environment, s, width=79, break_long_words=True, wrapstring=None
     split words apart if they are longer than `width`.
     """
     if not s:
-    	return s
+        return s
     
     if not wrapstring:
         wrapstring = environment.newline_sequence
@@ -220,7 +220,7 @@ def do_wordwrap(environment, s, width=79, break_long_words=True, wrapstring=None
     # Workaround: pre-split the string on \r, \r\n and \n
     for component in re.split(r"\r\n|\n|\r", s):
         # textwrap will eat empty strings for breakfirst. Therefore we route them around it.
-        if len(component) is 0:
+        if len(component) == 0:
             accumulator.append(component)
             continue
         accumulator.extend(
diff --git a/fhirspec.py b/fhirspec.py
index 3a9fa692..a7ec0d66 100644
--- a/fhirspec.py
+++ b/fhirspec.py
@@ -623,7 +623,7 @@ def needed_external_classes(self):
                         raise Exception('There is no class "{}" for property "{}" on "{}" in {}'.format(prop_cls_name, prop.name, klass.name, self.name))
                     else:
                         prop.module_name = prop_cls.module
-                        if not prop_cls_name in needed:
+                        if prop_cls_name not in needed:
                             needed.add(prop_cls_name)
                             needs.append(prop_cls)
         
diff --git a/requirements.txt b/requirements.txt
index eb82609a..182c0095 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-Jinja2>=2.9.5
+Jinja2>=3.0
 MarkupSafe==0.23
 requests>=2.13.0
 colorlog==2.10.0