diff --git a/models/spring-ai-ollama/src/main/java/org/springframework/ai/ollama/api/OllamaApiHelper.java b/models/spring-ai-ollama/src/main/java/org/springframework/ai/ollama/api/OllamaApiHelper.java
index 4e4c1a0c151..fd0da1f12b6 100644
--- a/models/spring-ai-ollama/src/main/java/org/springframework/ai/ollama/api/OllamaApiHelper.java
+++ b/models/spring-ai-ollama/src/main/java/org/springframework/ai/ollama/api/OllamaApiHelper.java
@@ -63,7 +63,7 @@ public static boolean isStreamingDone(OllamaApi.ChatResponse ollamaChatResponse)
 
 	public static ChatResponse merge(ChatResponse previous, ChatResponse current) {
 
-		String model = merge(previous.model(), current.model());
+		String model = (current.model() != null ? current.model() : previous.model());
 		Instant createdAt = merge(previous.createdAt(), current.createdAt());
 		OllamaApi.Message message = merge(previous.message(), current.message());
 		String doneReason = (current.doneReason() != null ? current.doneReason() : previous.doneReason());
@@ -122,16 +122,6 @@ private static Long merge(Long previous, Long current) {
 		return previous + current;
 	}
 
-	private static String merge(String previous, String current) {
-		if (previous == null) {
-			return current;
-		}
-		if (current == null) {
-			return previous;
-		}
-		return previous + current;
-	}
-
 	private static String mergeContent(OllamaApi.Message previous, OllamaApi.Message current) {
 		if (previous == null || previous.content() == null) {
 			return (current != null ? current.content() : null);
diff --git a/models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/api/OllamaApiHelperTests.java b/models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/api/OllamaApiHelperTests.java
index 3ef110ffd7f..6f43551b90b 100644
--- a/models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/api/OllamaApiHelperTests.java
+++ b/models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/api/OllamaApiHelperTests.java
@@ -149,7 +149,7 @@ void mergeWhenBothResponsesHaveValuesShouldMergeCorrectly() {
 
 		OllamaApi.ChatResponse result = OllamaApiHelper.merge(previous, current);
 
-		assertThat(result.model()).isEqualTo("previous-modelcurrent-model");
+		assertThat(result.model()).isEqualTo("current-model");
 		assertThat(result.createdAt()).isEqualTo(currentCreatedAt);
 		assertThat(result.message().content()).isEqualTo("Previous contentCurrent content");
 		assertThat(result.message().thinking()).isEqualTo("Previous thinkingCurrent thinking");
@@ -187,7 +187,6 @@ void mergeStringsShouldConcatenate() {
 
 		OllamaApi.ChatResponse result = OllamaApiHelper.merge(previous, current);
 
-		assertThat(result.model()).isEqualTo("model1model2");
 		assertThat(result.message().content()).isEqualTo("Hello World");
 		assertThat(result.message().thinking()).isEqualTo("Thinking");
 		assertThat(result.message().toolName()).isEqualTo("ToolBox");