diff --git a/models/spring-ai-google-genai/src/main/java/org/springframework/ai/google/genai/GoogleGenAiChatOptions.java b/models/spring-ai-google-genai/src/main/java/org/springframework/ai/google/genai/GoogleGenAiChatOptions.java
index 8c7237caff..72a9c73a64 100644
--- a/models/spring-ai-google-genai/src/main/java/org/springframework/ai/google/genai/GoogleGenAiChatOptions.java
+++ b/models/spring-ai-google-genai/src/main/java/org/springframework/ai/google/genai/GoogleGenAiChatOptions.java
@@ -186,7 +186,7 @@ public class GoogleGenAiChatOptions implements ToolCallingChatOptions, Structure
 	/**
 	 * Use Google search Grounding feature
 	 */
-	private final Boolean googleSearchRetrieval;
+	private final @Nullable Boolean googleSearchRetrieval;
 
 	/**
 	 * Optional. When true, the API response will include server-side tool calls and
@@ -194,7 +194,7 @@ public class GoogleGenAiChatOptions implements ToolCallingChatOptions, Structure
 	 * This allows clients to observe the server's tool invocations without executing them.
 	 * Only supported with MLDev (Google AI) API, not Vertex AI.
 	 */
-	private final Boolean includeServerSideToolInvocations;
+	private final @Nullable Boolean includeServerSideToolInvocations;
 
 	private final @Nullable List<GoogleGenAiSafetySetting> safetySettings;
 
@@ -240,8 +240,8 @@ protected GoogleGenAiChatOptions(@Nullable String model, @Nullable Double freque
 		this.useCachedContent = useCachedContent;
 		this.autoCacheThreshold = autoCacheThreshold;
 		this.autoCacheTtl = autoCacheTtl;
-		this.googleSearchRetrieval = Boolean.TRUE.equals(googleSearchRetrieval);
-		this.includeServerSideToolInvocations = Boolean.TRUE.equals(includeServerSideToolInvocations);
+		this.googleSearchRetrieval = googleSearchRetrieval;
+		this.includeServerSideToolInvocations = includeServerSideToolInvocations;
 		this.safetySettings = (safetySettings != null ? List.copyOf(safetySettings) : null);
 		this.labels = (labels != null ? Map.copyOf(labels) : null);
 		this.serviceTier = serviceTier;
diff --git a/models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/GoogleGenAiChatOptionsTest.java b/models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/GoogleGenAiChatOptionsTest.java
index 07940f5b27..f1fe1bcac3 100644
--- a/models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/GoogleGenAiChatOptionsTest.java
+++ b/models/spring-ai-google-genai/src/test/java/org/springframework/ai/google/genai/GoogleGenAiChatOptionsTest.java
@@ -212,6 +212,45 @@ public void testEqualsAndHashCodeWithIncludeServerSideToolInvocations() {
 		assertThat(options1).isNotEqualTo(options3);
 	}
 
+	@Test
+	public void testOptionalBooleanDefaultsRemainUnset() {
+		GoogleGenAiChatOptions options = GoogleGenAiChatOptions.builder().build();
+
+		assertThat(options.getGoogleSearchRetrieval()).isNull();
+		assertThat(options.getIncludeServerSideToolInvocations()).isNull();
+	}
+
+	@Test
+	public void testCombineWithPreservesOptionalBooleanDefaults() {
+		GoogleGenAiChatOptions defaults = GoogleGenAiChatOptions.builder()
+			.googleSearchRetrieval(true)
+			.includeServerSideToolInvocations(true)
+			.build();
+		GoogleGenAiChatOptions requestOptions = GoogleGenAiChatOptions.builder().temperature(0.2).build();
+
+		GoogleGenAiChatOptions merged = defaults.mutate().combineWith(requestOptions.mutate()).build();
+
+		assertThat(merged.getGoogleSearchRetrieval()).isTrue();
+		assertThat(merged.getIncludeServerSideToolInvocations()).isTrue();
+	}
+
+	@Test
+	public void testCombineWithOverridesOptionalBooleansWhenExplicitlySet() {
+		GoogleGenAiChatOptions defaults = GoogleGenAiChatOptions.builder()
+			.googleSearchRetrieval(true)
+			.includeServerSideToolInvocations(true)
+			.build();
+		GoogleGenAiChatOptions requestOptions = GoogleGenAiChatOptions.builder()
+			.googleSearchRetrieval(false)
+			.includeServerSideToolInvocations(false)
+			.build();
+
+		GoogleGenAiChatOptions merged = defaults.mutate().combineWith(requestOptions.mutate()).build();
+
+		assertThat(merged.getGoogleSearchRetrieval()).isFalse();
+		assertThat(merged.getIncludeServerSideToolInvocations()).isFalse();
+	}
+
 	@Test
 	public void testServiceTierWithBuilder() {
 		GoogleGenAiChatOptions options = GoogleGenAiChatOptions.builder()