diff --git a/infinity/build.gradle b/infinity/build.gradle
index 60236379..56293c7d 100644
--- a/infinity/build.gradle
+++ b/infinity/build.gradle
@@ -28,7 +28,7 @@ dependencies {
     implementation "org.apache.logging.log4j:log4j-api:$log4jVersion"
     implementation "org.apache.logging.log4j:log4j-core:$log4jVersion"
     runtimeOnly "org.apache.logging.log4j:log4j-slf4j-impl:$log4jVersion"
-    implementation 'com.github.stephengold:Heart:8.2.0'
+    implementation 'com.github.stephengold:Heart:9.1.0'
 
     //https://mvnrepository.com/artifact/com.google.code.findbugs/jsr305
     implementation "com.google.code.findbugs:jsr305:3.0.2"