diff --git a/rxlib/src/main/java/org/rx/core/EventBus.java b/rxlib/src/main/java/org/rx/core/EventBus.java
index 8289d287..bd5d0b43 100644
--- a/rxlib/src/main/java/org/rx/core/EventBus.java
+++ b/rxlib/src/main/java/org/rx/core/EventBus.java
@@ -89,7 +89,7 @@ Map<Class<?>, Set<Tuple<Object, Method>>> findAllSubscribers(Object listener) {
         Map<Class<?>, Set<Tuple<Object, Method>>> methodsInListener = new HashMap<>();
         for (Method method : Linq.from(Reflects.getMethodMap(listener instanceof Class ? (Class<?>) listener : listener.getClass()).values()).selectMany(p -> p).where(p -> p.isAnnotationPresent(Subscribe.class) && !p.isSynthetic())) {
             if (method.getParameterCount() != 1) {
-                throw new InvalidException("Subscriber method %s has @Subscribe annotation must have exactly 1 parameter.", method);
+                throw new InvalidException("Subscriber method {} has @Subscribe annotation must have exactly 1 parameter.", method);
             }
             Class<?> eventType = method.getParameterTypes()[0];
             methodsInListener.computeIfAbsent(eventType, k -> new HashSet<>()).add(Tuple.of(listener, method));
diff --git a/rxlib/src/main/java/org/rx/core/FluentWait.java b/rxlib/src/main/java/org/rx/core/FluentWait.java
index 16fc2f45..cd8b3074 100644
--- a/rxlib/src/main/java/org/rx/core/FluentWait.java
+++ b/rxlib/src/main/java/org/rx/core/FluentWait.java
@@ -42,6 +42,7 @@ public static <T> FluentWait polling(long timeoutMillis, long intervalMillis, Bi
     private BiFunc<FluentWait, Object> resultFunc;
     private List<Class<? extends Throwable>> ignoredExceptions;
     private String message;
+    private boolean initialDelay;
     private long retryMillis = TIMEOUT_INFINITE;
     private BiAction<FluentWait> retryFunc;
     private boolean retryOnStart;
@@ -63,6 +64,11 @@ public synchronized FluentWait withMessage(String message) {
         return this;
     }
 
+    public synchronized FluentWait withInitialDelay() {
+        this.initialDelay = true;
+        return this;
+    }
+
     public FluentWait retryEvery(long interval, BiAction<FluentWait> retryFunc) {
         return retryEvery(interval, retryFunc, false);
     }
@@ -135,6 +141,9 @@ public synchronized <T> T await(@NonNull BiFunc<FluentWait, T> resultFunc) throw
             boolean doRetry = retryCount > TIMEOUT_INFINITE;
             Throwable cause;
             T result = null;
+            if (initialDelay) {
+                sleep(interval);
+            }
             do {
                 try {
                     if ((result = resultFunc.invoke(this)) != null) {