diff --git a/build.gradle b/build.gradle
index cbba262b..fb8ee6ec 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,7 +17,7 @@ dependencies {
   compile "org.jetbrains:markdown:${markdownParserVersion}"
   compile "org.jetbrains.kotlin:kotlin-reflect:1.4.21"
   compile "org.jetbrains.kotlin:kotlin-stdlib:1.4.21"
-  compile "io.reactivex.rxjava2:rxjava:2.2.9"
+  compile "io.reactivex.rxjava2:rxjava:2.2.21"
 
   testCompile group: 'junit', name: 'junit', version: '4.12'
   testImplementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7"