diff --git a/build.gradle b/build.gradle
index a9a126db..9522dc64 100644
--- a/build.gradle
+++ b/build.gradle
@@ -60,7 +60,7 @@ subprojects {
             }
 
             testRuntimeOnly "org.junit.platform:junit-platform-launcher"
-            testRuntimeOnly "net.bytebuddy:byte-buddy:1.17.7"
+            testRuntimeOnly "net.bytebuddy:byte-buddy:1.18.3"
             // allows Spock to mock classes (in addition to interfaces)
             testRuntimeOnly "org.objenesis:objenesis:3.4"
             // Allow Spock to mock classes with constructor arguments
diff --git a/cj-btc-cli/build.gradle b/cj-btc-cli/build.gradle
index ced2d19d..46572efe 100644
--- a/cj-btc-cli/build.gradle
+++ b/cj-btc-cli/build.gradle
@@ -41,7 +41,7 @@ testing {
                     exclude module: "groovy-all"
                 }
 
-                runtimeOnly "net.bytebuddy:byte-buddy:1.17.7"
+                runtimeOnly "net.bytebuddy:byte-buddy:1.18.3"
                 // allows Spock to mock classes (in addition to interfaces)
                 runtimeOnly "org.objenesis:objenesis:3.4"
                 // Allow Spock to mock classes with constructor arguments
diff --git a/cj-btc-jsonrpc-integ-test/build.gradle b/cj-btc-jsonrpc-integ-test/build.gradle
index 9a9a2684..9f808632 100644
--- a/cj-btc-jsonrpc-integ-test/build.gradle
+++ b/cj-btc-jsonrpc-integ-test/build.gradle
@@ -20,7 +20,7 @@ testing {
                     transitive = false
                 }
 
-                runtimeOnly "net.bytebuddy:byte-buddy:1.17.7"       // Allows Spock to mock classes (in addition to interfaces)
+                runtimeOnly "net.bytebuddy:byte-buddy:1.18.3"       // Allows Spock to mock classes (in addition to interfaces)
                 runtimeOnly "org.objenesis:objenesis:3.4"           // Allows Spock to mock classes with constructor arguments
                 runtimeOnly "org.slf4j:slf4j-jdk14:${slf4jVersion}" // Runtime implementation of slf4j
             }