diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 41ae387e5..275f0a8a4 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -16,7 +16,7 @@ logback = "ch.qos.logback:logback-classic:1.2.10"
 mockito = "org.mockito:mockito-core:4.3.1"
 quickTheories = "org.quicktheories:quicktheories:0.25"
 reactiveStreams-tck = { module = "org.reactivestreams:reactive-streams-tck", version.ref = "reactiveStreams" }
-rxJava2 = "io.reactivex.rxjava2:rxjava:2.2.8"
+rxJava2 = "io.reactivex.rxjava2:rxjava:2.2.21"
 rxJava3 = "io.reactivex.rxjava3:rxjava:3.1.5"
 slf4j = "org.slf4j:slf4j-api:1.7.36"
 swt-windows = { module = "org.eclipse.swt:org.eclipse.swt.win32.win32.x86", version.ref = "swt" }