diff --git a/src/main/java/dev/openfeature/sdk/AbstractStructure.java b/src/main/java/dev/openfeature/sdk/AbstractStructure.java
index a7d7c2eae..e50fbe920 100644
--- a/src/main/java/dev/openfeature/sdk/AbstractStructure.java
+++ b/src/main/java/dev/openfeature/sdk/AbstractStructure.java
@@ -13,7 +13,7 @@ abstract class AbstractStructure implements Structure {
     }
 
     AbstractStructure(Map<String, Value> attributes) {
-        this.attributes = attributes;
+        this.attributes = new HashMap<>(attributes);
     }
 
     /**
diff --git a/src/main/java/dev/openfeature/sdk/ImmutableContext.java b/src/main/java/dev/openfeature/sdk/ImmutableContext.java
index 632448aae..1a1db8ec5 100644
--- a/src/main/java/dev/openfeature/sdk/ImmutableContext.java
+++ b/src/main/java/dev/openfeature/sdk/ImmutableContext.java
@@ -52,9 +52,12 @@ public ImmutableContext(Map<String, Value> attributes) {
      */
     public ImmutableContext(String targetingKey, Map<String, Value> attributes) {
         if (targetingKey != null && !targetingKey.trim().isEmpty()) {
-            attributes.put(TARGETING_KEY, new Value(targetingKey));
+            final Map<String, Value> actualAttribs = new HashMap<>(attributes);
+            actualAttribs.put(TARGETING_KEY, new Value(targetingKey));
+            this.structure = new ImmutableStructure(actualAttribs);
+        } else {
+            this.structure = new ImmutableStructure(attributes);
         }
-        this.structure = new ImmutableStructure(attributes);
     }
 
     /**
diff --git a/src/main/java/dev/openfeature/sdk/MutableContext.java b/src/main/java/dev/openfeature/sdk/MutableContext.java
index 69c22b841..bd6c8affb 100644
--- a/src/main/java/dev/openfeature/sdk/MutableContext.java
+++ b/src/main/java/dev/openfeature/sdk/MutableContext.java
@@ -42,10 +42,10 @@ public MutableContext(Map<String, Value> attributes) {
      * @param attributes   evaluation context attributes
      */
     public MutableContext(String targetingKey, Map<String, Value> attributes) {
+        this.structure = new MutableStructure(attributes);
         if (targetingKey != null && !targetingKey.trim().isEmpty()) {
-            attributes.put(TARGETING_KEY, new Value(targetingKey));
+            this.structure.attributes.put(TARGETING_KEY, new Value(targetingKey));
         }
-        this.structure = new MutableStructure(attributes);
     }
 
     // override @Delegate methods so that we can use "add" methods and still return MutableContext, not Structure