diff --git a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AbstractQueryMethod.java b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AbstractQueryMethod.java
index 28ab4bf7aa..9aaac3c190 100644
--- a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AbstractQueryMethod.java
+++ b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AbstractQueryMethod.java
@@ -204,7 +204,15 @@ public abstract class AbstractQueryMethod implements MetaAttribute {
 
 	void chainSessionEnd(boolean isUpdate, StringBuilder declaration) {
 		if ( isReactiveSession() ) {
-			declaration.append("\n\t});");
+			declaration.append("\n\t})");
+			// here we're checking for a boxed void and not Uni<Void> because the returnType has already
+			// been checked, and is ununi-ed
+			if ( isUpdate && returnTypeName != null && returnTypeName.equals(BOXED_VOID) ) {
+				declaration.append(".replaceWithVoid();");
+			}
+			else {
+				declaration.append(";");
+			}
 		}
 	}
 
@@ -445,7 +453,7 @@ public abstract class AbstractQueryMethod implements MetaAttribute {
 					.append(" _results = ");
 		}
 		else {
-			if ( !"void".equals(returnTypeName) ) {
+			if ( !"void".equals(returnTypeName) || isReactiveSession() ) {
 				declaration
 						.append("return ");
 			}
diff --git a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AnnotationMetaEntity.java b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AnnotationMetaEntity.java
index 51175a48aa..e0aa903cd2 100644
--- a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AnnotationMetaEntity.java
+++ b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/annotation/AnnotationMetaEntity.java
@@ -1558,16 +1558,33 @@ public class AnnotationMetaEntity extends AnnotationMeta {
 			@Nullable TypeMirror returnType,
 			AnnotationMirror mirror,
 			AnnotationValue value) {
-		if ( returnType == null
-				|| returnType.getKind() != TypeKind.VOID
-				&& returnType.getKind() != TypeKind.BOOLEAN
-				&& returnType.getKind() != TypeKind.INT ) {
+		boolean reactive = usingReactiveSession( sessionType );
+		if ( !isValidUpdateReturnType( returnType, method, reactive ) ) {
 			context.message( method, mirror, value,
-					"return type of mutation query method must be 'int', 'boolean', or 'void'",
+					"return type of mutation query method must be " + (!reactive ? "'int', 'boolean' or 'void'" : "'Uni<Integer>', 'Uni<Boolean>' or 'Uni<Void>'"),
 					Diagnostic.Kind.ERROR );
 		}
 	}
 
+	private boolean isValidUpdateReturnType(@Nullable TypeMirror returnType, ExecutableElement method, boolean reactive) {
+		if ( returnType == null ) {
+			return false;
+		}
+		if ( reactive ) {
+			// for reactive calls, don't use the returnType param, which has been ununi-ed, we want to check the full one
+			return method.getReturnType().toString().equals( Constants.UNI_VOID )
+					|| method.getReturnType().toString().equals( Constants.UNI_BOOLEAN )
+					|| method.getReturnType().toString().equals( Constants.UNI_INTEGER );
+			
+		}
+		else {
+			// non-reactive
+			return returnType.getKind() == TypeKind.VOID
+					|| returnType.getKind() == TypeKind.BOOLEAN
+					|| returnType.getKind() == TypeKind.INT;
+		}
+	}
+
 	private void validateSelectHql(
 			ExecutableElement method,
 			@Nullable TypeMirror returnType,
@@ -1955,7 +1972,8 @@ public class AnnotationMetaEntity extends AnnotationMeta {
 	}
 
 	private boolean usingReactiveSession(String sessionType) {
-		return Constants.MUTINY_SESSION.equals(sessionType);
+		return Constants.MUTINY_SESSION.equals(sessionType)
+				|| Constants.UNI_MUTINY_SESSION.equals(sessionType);
 	}
 
 	private boolean usingStatelessSession(String sessionType) {
diff --git a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/Constants.java b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/Constants.java
index 747ee3eb4d..41eeb596ce 100644
--- a/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/Constants.java
+++ b/tooling/metamodel-generator/src/main/java/org/hibernate/jpamodelgen/util/Constants.java
@@ -99,6 +99,10 @@ public final class Constants {
 
 	public static final String UNI = "io.smallrye.mutiny.Uni";
 	public static final String UNI_MUTINY_SESSION = UNI+"<org.hibernate.reactive.mutiny.Mutiny.Session>";
+	public static final String UNI_INTEGER = UNI+"<java.lang.Integer>";
+	public static final String UNI_VOID = UNI+"<java.lang.Void>";
+	public static final String UNI_BOOLEAN = UNI+"<java.lang.Boolean>";
+	public static final String BOXED_VOID = Void.class.getName();
 
 	public static final String SINGULAR_ATTRIBUTE = "jakarta.persistence.metamodel.SingularAttribute";
 	public static final String COLLECTION_ATTRIBUTE = "jakarta.persistence.metamodel.CollectionAttribute";