diff --git a/build.gradle b/build.gradle
index c651fa54..4139cfc6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -121,7 +121,7 @@ subprojects { Project subproject ->
         }
 
         dependencies {
-            testImplementation "io.projectreactor:reactor-test:3.4.18"
+            testImplementation "io.projectreactor:reactor-test:3.4.21"
             testImplementation "org.codehaus.groovy:groovy-test-junit5:$groovyVersion"
             testImplementation("org.spockframework:spock-core:$spockVersion") { transitive = false}
             testImplementation "org.junit.jupiter:junit-jupiter-api:$junitJupiterVersion"