diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/EmptyTaskSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/EmptyTaskSettingsTests.java
index 5a51e89f57e11..060dc23b935cc 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/EmptyTaskSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/EmptyTaskSettingsTests.java
@@ -29,6 +29,7 @@ protected EmptyTaskSettings createTestInstance() {
 
     @Override
     protected EmptyTaskSettings mutateInstance(EmptyTaskSettings instance) {
+        // All instances are the same and have no fields, nothing to mutate
         return null;
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/action/InferenceActionResponseTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/action/InferenceActionResponseTests.java
index 7016122fedcf8..428dbca892438 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/action/InferenceActionResponseTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/action/InferenceActionResponseTests.java
@@ -53,7 +53,7 @@ protected InferenceAction.Response createTestInstance() {
 
     @Override
     protected InferenceAction.Response mutateInstance(InferenceAction.Response instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, this::createTestInstance);
     }
 
     @Override
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedSparseEmbeddingResultsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedSparseEmbeddingResultsTests.java
index 9484763912cda..4be38b9d0e9d0 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedSparseEmbeddingResultsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedSparseEmbeddingResultsTests.java
@@ -132,6 +132,6 @@ protected ChunkedSparseEmbeddingResults createTestInstance() {
 
     @Override
     protected ChunkedSparseEmbeddingResults mutateInstance(ChunkedSparseEmbeddingResults instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, ChunkedSparseEmbeddingResultsTests::createRandomResults);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingByteResultsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingByteResultsTests.java
index c908d2c85f620..05b86217862e9 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingByteResultsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingByteResultsTests.java
@@ -131,6 +131,6 @@ protected ChunkedTextEmbeddingByteResults createTestInstance() {
 
     @Override
     protected ChunkedTextEmbeddingByteResults mutateInstance(ChunkedTextEmbeddingByteResults instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, ChunkedTextEmbeddingByteResultsTests::createRandomResults);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingFloatResultsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingFloatResultsTests.java
index 9b18f5536713e..966a639713ba6 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingFloatResultsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingFloatResultsTests.java
@@ -51,6 +51,6 @@ protected ChunkedTextEmbeddingFloatResults createTestInstance() {
 
     @Override
     protected ChunkedTextEmbeddingFloatResults mutateInstance(ChunkedTextEmbeddingFloatResults instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, this::createTestInstance);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingResultsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingResultsTests.java
index 9e827b51d50f6..fd0c8b19aae24 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingResultsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/results/ChunkedTextEmbeddingResultsTests.java
@@ -159,6 +159,6 @@ protected ChunkedTextEmbeddingResults createTestInstance() {
 
     @Override
     protected ChunkedTextEmbeddingResults mutateInstance(ChunkedTextEmbeddingResults instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, ChunkedTextEmbeddingResultsTests::createRandomResults);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/AzureOpenAiSecretSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/AzureOpenAiSecretSettingsTests.java
index d2b83d7b14e2b..bfff26bcaefc0 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/AzureOpenAiSecretSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/AzureOpenAiSecretSettingsTests.java
@@ -143,7 +143,7 @@ protected AzureOpenAiSecretSettings createTestInstance() {
 
     @Override
     protected AzureOpenAiSecretSettings mutateInstance(AzureOpenAiSecretSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, AzureOpenAiSecretSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getAzureOpenAiSecretSettingsMap(@Nullable String apiKey, @Nullable String entraId) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionServiceSettingsTests.java
index cbaa41c37958d..46e514c8b16c4 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionServiceSettingsTests.java
@@ -87,6 +87,6 @@ protected AzureOpenAiCompletionServiceSettings createTestInstance() {
 
     @Override
     protected AzureOpenAiCompletionServiceSettings mutateInstance(AzureOpenAiCompletionServiceSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, AzureOpenAiCompletionServiceSettingsTests::createRandom);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionTaskSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionTaskSettingsTests.java
index 7f0e730b8835c..15e1d8d7809c5 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionTaskSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/completion/AzureOpenAiCompletionTaskSettingsTests.java
@@ -94,6 +94,6 @@ protected AzureOpenAiCompletionTaskSettings createTestInstance() {
 
     @Override
     protected AzureOpenAiCompletionTaskSettings mutateInstance(AzureOpenAiCompletionTaskSettings instance) throws IOException {
-        return createRandomWithUser();
+        return randomValueOtherThan(instance, AzureOpenAiCompletionTaskSettingsTests::createRandomWithUser);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsServiceSettingsTests.java
index 7c56ffad27c80..f4c6f9b2a4f07 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsServiceSettingsTests.java
@@ -423,7 +423,7 @@ protected AzureOpenAiEmbeddingsServiceSettings createTestInstance() {
 
     @Override
     protected AzureOpenAiEmbeddingsServiceSettings mutateInstance(AzureOpenAiEmbeddingsServiceSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, AzureOpenAiEmbeddingsServiceSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getPersistentAzureOpenAiServiceSettingsMap(
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsTaskSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsTaskSettingsTests.java
index cc2d8b9b67620..324bdd15d9256 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsTaskSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/azureopenai/embeddings/AzureOpenAiEmbeddingsTaskSettingsTests.java
@@ -92,7 +92,7 @@ protected AzureOpenAiEmbeddingsTaskSettings createTestInstance() {
 
     @Override
     protected AzureOpenAiEmbeddingsTaskSettings mutateInstance(AzureOpenAiEmbeddingsTaskSettings instance) throws IOException {
-        return createRandomWithUser();
+        return randomValueOtherThan(instance, AzureOpenAiEmbeddingsTaskSettingsTests::createRandomWithUser);
     }
 
     public static Map<String, Object> getAzureOpenAiRequestTaskSettingsMap(@Nullable String user) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/CohereServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/CohereServiceSettingsTests.java
index a010f63802052..303ed1cab2c50 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/CohereServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/CohereServiceSettingsTests.java
@@ -275,7 +275,7 @@ protected CohereServiceSettings createTestInstance() {
 
     @Override
     protected CohereServiceSettings mutateInstance(CohereServiceSettings instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, CohereServiceSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getServiceSettingsMap(@Nullable String url, @Nullable String model) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsServiceSettingsTests.java
index a306a3e660cd9..6f8fe6344b57f 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsServiceSettingsTests.java
@@ -358,7 +358,7 @@ protected CohereEmbeddingsServiceSettings createTestInstance() {
 
     @Override
     protected CohereEmbeddingsServiceSettings mutateInstance(CohereEmbeddingsServiceSettings instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, CohereEmbeddingsServiceSettingsTests::createRandom);
     }
 
     @Override
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsTaskSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsTaskSettingsTests.java
index 4f5d872f09eb8..c18310eb9a84a 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsTaskSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/embeddings/CohereEmbeddingsTaskSettingsTests.java
@@ -156,7 +156,7 @@ protected CohereEmbeddingsTaskSettings createTestInstance() {
 
     @Override
     protected CohereEmbeddingsTaskSettings mutateInstance(CohereEmbeddingsTaskSettings instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, CohereEmbeddingsTaskSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getTaskSettingsMapEmpty() {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/rerank/CohereRerankServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/rerank/CohereRerankServiceSettingsTests.java
index cb30077fec174..4943ddf74fda1 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/rerank/CohereRerankServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/cohere/rerank/CohereRerankServiceSettingsTests.java
@@ -77,7 +77,7 @@ protected CohereRerankServiceSettings createTestInstance() {
 
     @Override
     protected CohereRerankServiceSettings mutateInstance(CohereRerankServiceSettings instance) throws IOException {
-        return null;
+        return randomValueOtherThan(instance, CohereRerankServiceSettingsTests::createRandom);
     }
 
     @Override
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceServiceSettingsTests.java
index d81c94a0dedda..9d92f756dd31c 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/HuggingFaceServiceSettingsTests.java
@@ -197,7 +197,7 @@ protected HuggingFaceServiceSettings createTestInstance() {
 
     @Override
     protected HuggingFaceServiceSettings mutateInstance(HuggingFaceServiceSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, HuggingFaceServiceSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getServiceSettingsMap(String url) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserSecretSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserSecretSettingsTests.java
index 2b8281da8db13..f69a9b5a967e0 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserSecretSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserSecretSettingsTests.java
@@ -77,6 +77,6 @@ protected HuggingFaceElserSecretSettings createTestInstance() {
 
     @Override
     protected HuggingFaceElserSecretSettings mutateInstance(HuggingFaceElserSecretSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, HuggingFaceElserSecretSettingsTests::createRandom);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserServiceSettingsTests.java
index eadefddecce70..bd6a5007b72ee 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/huggingface/elser/HuggingFaceElserServiceSettingsTests.java
@@ -122,6 +122,6 @@ protected HuggingFaceElserServiceSettings createTestInstance() {
 
     @Override
     protected HuggingFaceElserServiceSettings mutateInstance(HuggingFaceElserServiceSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, HuggingFaceElserServiceSettingsTests::createRandom);
     }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/completion/OpenAiChatCompletionServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/completion/OpenAiChatCompletionServiceSettingsTests.java
index b9b4310699d07..75ea63eba8a34 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/completion/OpenAiChatCompletionServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/completion/OpenAiChatCompletionServiceSettingsTests.java
@@ -236,7 +236,7 @@ protected OpenAiChatCompletionServiceSettings createTestInstance() {
 
     @Override
     protected OpenAiChatCompletionServiceSettings mutateInstance(OpenAiChatCompletionServiceSettings instance) throws IOException {
-        return createRandomWithNonNullUrl();
+        return randomValueOtherThan(instance, OpenAiChatCompletionServiceSettingsTests::createRandomWithNonNullUrl);
     }
 
     private static OpenAiChatCompletionServiceSettings createRandomWithNonNullUrl() {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsServiceSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsServiceSettingsTests.java
index c964d2643459d..1be70ee586835 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsServiceSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsServiceSettingsTests.java
@@ -441,7 +441,7 @@ protected OpenAiEmbeddingsServiceSettings createTestInstance() {
 
     @Override
     protected OpenAiEmbeddingsServiceSettings mutateInstance(OpenAiEmbeddingsServiceSettings instance) throws IOException {
-        return createRandomWithNonNullUrl();
+        return randomValueOtherThan(instance, OpenAiEmbeddingsServiceSettingsTests::createRandomWithNonNullUrl);
     }
 
     public static Map<String, Object> getServiceSettingsMap(String modelId, @Nullable String url, @Nullable String org) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsTaskSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsTaskSettingsTests.java
index c5a510ef9de0c..464f5a1885d99 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsTaskSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/openai/embeddings/OpenAiEmbeddingsTaskSettingsTests.java
@@ -97,7 +97,7 @@ protected OpenAiEmbeddingsTaskSettings createTestInstance() {
 
     @Override
     protected OpenAiEmbeddingsTaskSettings mutateInstance(OpenAiEmbeddingsTaskSettings instance) throws IOException {
-        return createRandomWithUser();
+        return randomValueOtherThan(instance, OpenAiEmbeddingsTaskSettingsTests::createRandomWithUser);
     }
 
     public static Map<String, Object> getTaskSettingsMap(@Nullable String user) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/DefaultSecretSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/DefaultSecretSettingsTests.java
index bd7a3ef4dcf03..212a867349e5c 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/DefaultSecretSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/DefaultSecretSettingsTests.java
@@ -75,7 +75,7 @@ protected DefaultSecretSettings createTestInstance() {
 
     @Override
     protected DefaultSecretSettings mutateInstance(DefaultSecretSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, DefaultSecretSettingsTests::createRandom);
     }
 
     public static Map<String, Object> getSecretSettingsMap(String apiKey) {
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/RateLimitSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/RateLimitSettingsTests.java
index 65bcaca981020..cdee7c452ff52 100644
--- a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/RateLimitSettingsTests.java
+++ b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/settings/RateLimitSettingsTests.java
@@ -100,6 +100,6 @@ protected RateLimitSettings createTestInstance() {
 
     @Override
     protected RateLimitSettings mutateInstance(RateLimitSettings instance) throws IOException {
-        return createRandom();
+        return randomValueOtherThan(instance, RateLimitSettingsTests::createRandom);
     }
 }