diff --git a/package-lock.json b/package-lock.json
index bdbaf0116..ff44513d6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -55694,7 +55694,7 @@
     },
     "packages/rum": {
       "name": "@elastic/apm-rum",
-      "version": "5.16.0",
+      "version": "5.16.1",
       "license": "MIT",
       "dependencies": {
         "@elastic/apm-rum-core": "file:../rum-core"
@@ -55705,7 +55705,7 @@
     },
     "packages/rum-angular": {
       "name": "@elastic/apm-rum-angular",
-      "version": "3.0.3",
+      "version": "3.0.4",
       "license": "MIT",
       "dependencies": {
         "@elastic/apm-rum": "file:../rum",
@@ -55727,7 +55727,7 @@
     },
     "packages/rum-core": {
       "name": "@elastic/apm-rum-core",
-      "version": "5.21.0",
+      "version": "5.21.1",
       "license": "MIT",
       "dependencies": {
         "error-stack-parser": "^1.3.5",
@@ -55740,7 +55740,7 @@
     },
     "packages/rum-react": {
       "name": "@elastic/apm-rum-react",
-      "version": "2.0.2",
+      "version": "2.0.3",
       "license": "MIT",
       "dependencies": {
         "@elastic/apm-rum": "file:../rum",
@@ -55764,7 +55764,7 @@
     },
     "packages/rum-vue": {
       "name": "@elastic/apm-rum-vue",
-      "version": "2.1.6",
+      "version": "2.1.7",
       "license": "MIT",
       "dependencies": {
         "@elastic/apm-rum": "file:../rum",
diff --git a/packages/rum-core/src/common/config-service.js b/packages/rum-core/src/common/config-service.js
index 97f94c44c..a11a52677 100644
--- a/packages/rum-core/src/common/config-service.js
+++ b/packages/rum-core/src/common/config-service.js
@@ -190,7 +190,7 @@ class Config {
         Math.round(transactionSampleRate * 10000) / 10000
     }
 
-    merge(this.config, properties)
+    this.config = merge(this.config, properties)
     this.events.send(CONFIG_CHANGE, [this.config])
   }
 
diff --git a/packages/rum-core/src/common/utils.js b/packages/rum-core/src/common/utils.js
index bb4ab85ea..cabb6aeec 100644
--- a/packages/rum-core/src/common/utils.js
+++ b/packages/rum-core/src/common/utils.js
@@ -284,12 +284,12 @@ function getCurrentScript() {
   }
 }
 
-function extend(dst) {
-  return baseExtend(dst, slice.call(arguments, 1), false)
+function extend() {
+  return baseExtend(Object.create(null), slice.call(arguments), false)
 }
 
-function merge(dst) {
-  return baseExtend(dst, slice.call(arguments, 1), true)
+function merge() {
+  return baseExtend(Object.create(null), slice.call(arguments), true)
 }
 
 function isUndefined(obj) {
diff --git a/packages/rum-core/src/performance-monitoring/span-base.js b/packages/rum-core/src/performance-monitoring/span-base.js
index f8318133c..a406ae566 100644
--- a/packages/rum-core/src/performance-monitoring/span-base.js
+++ b/packages/rum-core/src/performance-monitoring/span-base.js
@@ -77,7 +77,7 @@ class SpanBase {
   addContext(...context) {
     if (context.length === 0) return
     this.ensureContext()
-    merge(this.context, ...context)
+    this.context = merge(this.context, ...context)
   }
 
   end(endTime) {
diff --git a/packages/rum-core/src/performance-monitoring/transaction.js b/packages/rum-core/src/performance-monitoring/transaction.js
index c4d56e780..09f2d34f8 100644
--- a/packages/rum-core/src/performance-monitoring/transaction.js
+++ b/packages/rum-core/src/performance-monitoring/transaction.js
@@ -88,7 +88,7 @@ class Transaction extends SpanBase {
       // is not setting explicitly the threshold and instead expecting to rely on the one by default.
       this.options.reuseThreshold = options.reuseThreshold
 
-      extend(this.options, options)
+      this.options = extend(this.options, options)
     }
   }