diff --git a/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/FactCheckingEvaluator.java b/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/FactCheckingEvaluator.java
index 103e5d03796..0d6c27face3 100644
--- a/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/FactCheckingEvaluator.java
+++ b/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/FactCheckingEvaluator.java
@@ -138,7 +138,7 @@ public EvaluationResponse evaluate(EvaluationRequest evaluationRequest) {
 			.call()
 			.content();
 
-		boolean passing = "yes".equalsIgnoreCase(evaluationResponse);
+		boolean passing = evaluationResponse != null && evaluationResponse.toLowerCase().contains("yes");
 		return new EvaluationResponse(passing, "", Collections.emptyMap());
 	}
 
diff --git a/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/RelevancyEvaluator.java b/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/RelevancyEvaluator.java
index 9de2c181fe0..a2d1056bbec 100644
--- a/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/RelevancyEvaluator.java
+++ b/spring-ai-client-chat/src/main/java/org/springframework/ai/chat/evaluation/RelevancyEvaluator.java
@@ -77,12 +77,8 @@ public EvaluationResponse evaluate(EvaluationRequest evaluationRequest) {
 
 		String evaluationResponse = this.chatClientBuilder.build().prompt().user(userMessage).call().content();
 
-		boolean passing = false;
-		float score = 0;
-		if ("yes".equalsIgnoreCase(evaluationResponse)) {
-			passing = true;
-			score = 1;
-		}
+		boolean passing = evaluationResponse != null && evaluationResponse.toLowerCase().contains("yes");
+		float score = passing ? 1 : 0;
 
 		return new EvaluationResponse(passing, score, "", Collections.emptyMap());
 	}