diff --git a/.baseline/checkstyle/checkstyle.xml b/.baseline/checkstyle/checkstyle.xml
index 268ebe3f..43ec38a3 100644
--- a/.baseline/checkstyle/checkstyle.xml
+++ b/.baseline/checkstyle/checkstyle.xml
@@ -84,11 +84,13 @@
         <module name="AvoidStarImport"/> <!-- Java Style Guide: No wildcard imports -->
         <module name="AvoidStaticImport"> <!-- Java Style Guide: No static imports -->
             <property name="excludes" value="
+                com.google.common.base.Preconditions.*,
+                com.palantir.logsafe.Preconditions.*,
                 java.util.Collections.*,
                 java.util.stream.Collectors.*,
-                com.palantir.logsafe.Preconditions.*,
-                com.google.common.base.Preconditions.*,
-                org.apache.commons.lang3.Validate.*"/>
+                org.apache.commons.lang3.Validate.*,
+                org.assertj.core.api.Assertions.*,
+                org.mockito.Mockito.*"/>
         </module>
         <module name="ClassTypeParameterName"> <!-- Java Style Guide: Type variable names -->
             <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
@@ -469,7 +471,7 @@
         <module name="NestedTryDepth"/> <!-- Java Coding Guide: Try/catch blocks: never nested -->
         <module name="NonEmptyAtclauseDescription"/> <!-- Java Style Guide: At-clauses -->
         <module name="ParameterName"> <!-- Java Style Guide: Parameter names -->
-            <property name="format" value="^[a-z][a-zA-Z0-9]+$"/>
+            <property name="format" value="^_?[a-z][a-zA-Z0-9]+$"/>
             <message key="name.invalidPattern" value="Parameter name ''{0}'' must match pattern ''{1}''."/>
         </module>
         <module name="SingleLineJavadoc"/> <!-- Java Style Guide: General form -->
diff --git a/build.gradle b/build.gradle
index 8e82344e..2d5cbedd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -9,7 +9,7 @@ buildscript {
         classpath 'com.netflix.nebula:gradle-info-plugin:5.1.1'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.8.4'
         classpath 'com.netflix.nebula:nebula-publishing-plugin:14.0.0'
-        classpath 'com.palantir.baseline:gradle-baseline-java:2.4.0'
+        classpath 'com.palantir.baseline:gradle-baseline-java:2.20.1'
         classpath 'com.palantir.gradle.consistentversions:gradle-consistent-versions:1.12.4'
         classpath 'gradle.plugin.org.inferred:gradle-processors:3.1.0'
     }
diff --git a/sls-versions/src/test/java/com/palantir/sls/versions/OrderableSlsVersionTests.java b/sls-versions/src/test/java/com/palantir/sls/versions/OrderableSlsVersionTests.java
index aa7fa143..0ddceae0 100644
--- a/sls-versions/src/test/java/com/palantir/sls/versions/OrderableSlsVersionTests.java
+++ b/sls-versions/src/test/java/com/palantir/sls/versions/OrderableSlsVersionTests.java
@@ -116,7 +116,7 @@ public void testParsesStructureCorrectly() {
     public void testVersionIsEqualToItself() {
         for (String v : ORDERABLE_VERSIONS_IN_ORDER) {
             assertThat(OrderableSlsVersion.valueOf(v)).isEqualTo(OrderableSlsVersion.valueOf(v));
-            assertThat(compare(OrderableSlsVersion.valueOf(v), OrderableSlsVersion.valueOf(v))).isEqualTo(0);
+            assertThat(compare(OrderableSlsVersion.valueOf(v), OrderableSlsVersion.valueOf(v))).isZero();
         }
     }
 
@@ -203,7 +203,7 @@ private void assertVersionsInOrder(String smaller, String larger) {
     }
 
     private void assertVersionsEqual(String left, String right) {
-        assertThat(compare(OrderableSlsVersion.valueOf(left), OrderableSlsVersion.valueOf(right))).isEqualTo(0);
+        assertThat(compare(OrderableSlsVersion.valueOf(left), OrderableSlsVersion.valueOf(right))).isZero();
     }
 
     private OrderableSlsVersion version(