Index: src/OFThread.h
==================================================================
--- src/OFThread.h
+++ src/OFThread.h
@@ -95,10 +95,11 @@
 
 #ifdef OF_HAVE_CLASS_PROPERTIES
 # ifdef OF_HAVE_THREADS
 @property (class, readonly, nullable, nonatomic) OFThread *currentThread;
 @property (class, readonly, nullable, nonatomic) OFThread *mainThread;
+@property (class, readonly, nonatomic) bool isMainThread;
 @property (class, readonly, nullable, nonatomic)
     OFMutableDictionary *threadDictionary;
 @property (class, nullable, copy, nonatomic) OFString *name;
 # endif
 # ifdef OF_HAVE_SOCKETS
@@ -186,10 +187,17 @@
  *
  * @return The main thread
  */
 + (nullable OFThread *)mainThread;
 
+/*!
+ * @brief Returns whether the current thread is the main thread.
+ *
+ * @return Whether the current thread is the main thread.
+ */
++ (bool)isMainThread;
+
 /*!
  * @brief Returns a dictionary to store thread-specific data, meaning it
  *	  returns a different dictionary for every thread.
  *
  * @return A dictionary to store thread-specific data

Index: src/OFThread.m
==================================================================
--- src/OFThread.m
+++ src/OFThread.m
@@ -188,10 +188,18 @@
 
 + (OFThread *)mainThread
 {
 	return mainThread;
 }
+
++ (bool)isMainThread
+{
+	if (mainThread == nil)
+		return false;
+
+	return (of_tlskey_get(threadSelfKey) == mainThread);
+}
 
 + (OFMutableDictionary *)threadDictionary
 {
 	OFThread *thread = of_tlskey_get(threadSelfKey);