diff --git a/build.gradle b/build.gradle
index 9ee18cea3..ee3c2c50b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -54,32 +54,6 @@ subprojects {
         options.compilerArgs << '-Xlint:all,-overloads,-rawtypes,-unchecked'
     }
 
-    ext {
-        // common
-        jsr305Version = '3.0.2'
-        reactorVersion = '3.1.0.RELEASE'
-        nettyVersion = '4.1.15.Final'
-        reactiveStreamsVersion = '1.0.1'
-        slf4jVersion = '1.7.25'
-        // aeron
-        aeronVersion = '1.4.1'
-        // netty
-        reactorNettyVersion = '0.7.0.M2'
-        // spectator
-        spectatorVersion = '0.57.1'
-        hdrHistogramVersion = '2.1.9'
-        // tck-drivers
-        jacksonVersion = '2.9.1'
-        commonsLang3Version = '3.6'
-        airlineVersion = '0.8'
-        rxjavaVersion = '2.1.3'
-        // test
-        junitVersion = '4.12'
-        hamcrestVersion = '1.3'
-        mockitoVersion = '2.10.0'
-        jmhVersion = '1.19'
-    }
-
     // custom tasks for creating source/javadoc jars
     task sourcesJar(type: Jar, dependsOn: classes) {
         classifier = 'sources'
@@ -106,7 +80,7 @@ subprojects {
     }
 
     dependencies {
-        compile "io.projectreactor:reactor-core:3.1.0.RELEASE"
+        compile "io.projectreactor:reactor-core:3.1.1.RELEASE"
         compile "io.netty:netty-buffer:4.1.15.Final"
         compile "org.reactivestreams:reactive-streams:1.0.1"
         compile "org.slf4j:slf4j-api:1.7.25"
@@ -116,7 +90,7 @@ subprojects {
         testCompile "org.mockito:mockito-core:2.10.0"
         testCompile "org.hamcrest:hamcrest-library:1.3"
         testCompile "org.slf4j:slf4j-log4j12:1.7.25"
-        testCompile "io.projectreactor:reactor-test:3.1.0.RELEASE"
+        testCompile "io.projectreactor:reactor-test:3.1.1.RELEASE"
     }
 
     publishing {
diff --git a/rsocket-core/build.gradle b/rsocket-core/build.gradle
index c3a0645e8..ab9e9e05b 100644
--- a/rsocket-core/build.gradle
+++ b/rsocket-core/build.gradle
@@ -62,8 +62,8 @@ clean {
 }
 
 dependencies {
-    jmh "org.openjdk.jmh:jmh-core:${jmh.jmhVersion}"
-    jmh "org.openjdk.jmh:jmh-generator-annprocess:${jmh.jmhVersion}"
+    jmh "org.openjdk.jmh:jmh-core:1.19"
+    jmh "org.openjdk.jmh:jmh-generator-annprocess:1.19"
 
-    jmhRuntime "org.slf4j:slf4j-nop:$slf4jVersion"
-}
\ No newline at end of file
+    jmhRuntime "org.slf4j:slf4j-nop:1.7.25"
+}
diff --git a/rsocket-spectator/build.gradle b/rsocket-spectator/build.gradle
index f7eca3545..299648f07 100644
--- a/rsocket-spectator/build.gradle
+++ b/rsocket-spectator/build.gradle
@@ -16,7 +16,7 @@
 
 dependencies {
     compile project(':rsocket-core')
-    compile "com.netflix.spectator:spectator-api:$spectatorVersion"
+    compile "com.netflix.spectator:spectator-api:0.57.1"
     compile "org.hdrhistogram:HdrHistogram:2.1.9"
 
     testCompile project(':rsocket-test')
diff --git a/rsocket-transport-netty/build.gradle b/rsocket-transport-netty/build.gradle
index 1def42fb7..018cf6e25 100644
--- a/rsocket-transport-netty/build.gradle
+++ b/rsocket-transport-netty/build.gradle
@@ -16,11 +16,11 @@
 
 dependencies {
     compile project(':rsocket-core')
-    compile "io.projectreactor.ipc:reactor-netty:0.7.0.RELEASE"
-    compile "io.netty:netty-handler:4.1.15.Final"
-    compile "io.netty:netty-handler-proxy:4.1.15.Final"
-    compile "io.netty:netty-codec-http:4.1.15.Final"
-    compile "io.netty:netty-transport-native-epoll:4.1.15.Final"
+    compile "io.projectreactor.ipc:reactor-netty:0.7.1.RELEASE"
+    compile "io.netty:netty-handler:4.1.16.Final"
+    compile "io.netty:netty-handler-proxy:4.1.16.Final"
+    compile "io.netty:netty-codec-http:4.1.16.Final"
+    compile "io.netty:netty-transport-native-epoll:4.1.16.Final"
 
     testCompile project(':rsocket-test')
 }