diff --git a/build.gradle b/build.gradle
index 85035d7..4f4ca90 100644
--- a/build.gradle
+++ b/build.gradle
@@ -44,6 +44,14 @@ dependencies {
   testImplementation libs.checkerframework.qual
 }
 
+// To use a locally-built Checker Framework, run gradle with "-PcfLocal".
+if (hasProperty('cfLocal')) {
+  def cfHome = String.valueOf(System.getenv('CHECKERFRAMEWORK'))
+  dependencies {
+    testImplementation files(cfHome + '/checker/dist/checker.jar')
+  }
+}
+
 spotless {
   format 'misc', {
     // define the files to apply `misc` to
diff --git a/src/test/java/conformance/NullnessJSpecifyConformanceTest.java b/src/test/java/conformance/NullnessJSpecifyConformanceTest.java
index 28d70aa..da0389d 100644
--- a/src/test/java/conformance/NullnessJSpecifyConformanceTest.java
+++ b/src/test/java/conformance/NullnessJSpecifyConformanceTest.java
@@ -7,6 +7,8 @@
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSortedSet;
+
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -76,7 +78,7 @@ public void conformanceTests() throws IOException {
    * @param deps the dependencies of the conformance tests.
    */
   private static ImmutableSet<ReportedFact> analyze(
-      Path testDir, ImmutableList<Path> files, ImmutableList<Path> deps) {
+      Path testDir, ImmutableSortedSet<Path> files, ImmutableList<Path> deps) {
     ImmutableSet<File> fileInputs = files.stream().map(Path::toFile).collect(toImmutableSet());
 
     ImmutableList<String> depsAsStrings =