diff --git a/ros_buildfarm/scripts/release/generate_release_script.py b/ros_buildfarm/scripts/release/generate_release_script.py
index 4dd019c89..06031d0a9 100644
--- a/ros_buildfarm/scripts/release/generate_release_script.py
+++ b/ros_buildfarm/scripts/release/generate_release_script.py
@@ -16,8 +16,23 @@
 import re
 import sys
 
-from em import BANGPATH_OPT
-from em import Hook
+try:
+    # Import bangpath option name from EmPy v3
+    from em import BANGPATH_OPT
+    BANGPATH_VALUE = False
+except ImportError:
+    # EmPy 4 does not define an import-able constant for the updated bangpath
+    # option and inverts its meaning.
+    BANGPATH_OPT = 'ignoreBangpaths'
+    BANGPATH_VALUE = True
+
+
+try:
+    from em import Hook
+except:
+    from emlib import Hook
+
+
 from ros_buildfarm.argument import add_argument_arch
 from ros_buildfarm.argument import add_argument_build_name
 from ros_buildfarm.argument import add_argument_config_url
@@ -151,7 +166,7 @@ def beforeInclude(self, *args, **kwargs):
             'source_scripts': source_scripts,
             'binary_scripts': binary_scripts,
             'package_format': package_format},
-        options={BANGPATH_OPT: False})
+        options={BANGPATH_OPT: BANGPATH_VALUE})
     value = re.sub(r'(^| )python3 ', r'\1' + sys.executable + ' ', value, flags=re.M)
     print(value)
 
diff --git a/ros_buildfarm/templates/snippet/builder_parameterized-trigger.xml.em b/ros_buildfarm/templates/snippet/builder_parameterized-trigger.xml.em
index f919495c0..f59e6dd14 100644
--- a/ros_buildfarm/templates/snippet/builder_parameterized-trigger.xml.em
+++ b/ros_buildfarm/templates/snippet/builder_parameterized-trigger.xml.em
@@ -10,7 +10,7 @@
 @[if parameter_files]@
             <hudson.plugins.parameterizedtrigger.FileBuildParameters>
               <propertiesFile>@(','.join(ESCAPE(parameter_files)))</propertiesFile>
-              <failTriggerOnMissing>@(vars().get('missing_parameter_files_skip', False) ? 'true' : 'false')</failTriggerOnMissing>
+              <failTriggerOnMissing>@(vars().get('missing_parameter_files_skip', False) ? 'true' ! 'false')</failTriggerOnMissing>
               <textParamValueOnNewLine>false</textParamValueOnNewLine>
               <useMatrixChild>false</useMatrixChild>
               <onlyExactRuns>false</onlyExactRuns>
diff --git a/setup.py b/setup.py
index 3cdb734a5..af78f5af2 100644
--- a/setup.py
+++ b/setup.py
@@ -41,7 +41,7 @@
     'scripts': scripts,
     'zip_safe': False,
     'install_requires': [
-        'empy<4',
+        'empy',
         'PyYAML'],
     'extras_require': {
         'test': [