Index: src/OFStdIOStream.h
==================================================================
--- src/OFStdIOStream.h
+++ src/OFStdIOStream.h
@@ -150,16 +150,24 @@
  * @brief The standard error as an OFStream.
  */
 extern OFStdIOStream *_Nullable of_stderr;
 
 /*!
- * @brief Log the specified printf-style format to @ref of_stderr.
+ * @brief Logs the specified printf-style format to @ref of_stderr.
  *
  * This prefixes the output with the date, timestamp, process name and PID and
  * allows `%@` as a printf-style formatted to print objects.
  */
 extern void of_log(OFConstantString *format, ...);
+
+/*!
+ * @brief Logs the specified printf-style format to @ref of_stderr.
+ *
+ * This prefixes the output with the date, timestamp, process name and PID and
+ * allows `%@` as a printf-style formatted to print objects.
+ */
+extern void of_logv(OFConstantString *format, va_list arguments);
 #ifdef __cplusplus
 }
 #endif
 
 OF_ASSUME_NONNULL_END

Index: src/OFStdIOStream.m
==================================================================
--- src/OFStdIOStream.m
+++ src/OFStdIOStream.m
@@ -72,27 +72,34 @@
 #endif
 
 void
 of_log(OFConstantString *format, ...)
 {
+	va_list arguments;
+
+	va_start(arguments, format);
+	of_logv(format, arguments);
+	va_end(arguments);
+}
+
+void
+of_logv(OFConstantString *format, va_list arguments)
+{
 	void *pool = objc_autoreleasePoolPush();
 	OFDate *date;
 	OFString *dateString, *me, *msg;
-	va_list arguments;
 
 	date = [OFDate date];
 	dateString = [date localDateStringWithFormat: @"%Y-%m-%d %H:%M:%S"];
 #ifdef OF_HAVE_FILES
 	me = [OFApplication programName].lastPathComponent;
 #else
 	me = [OFApplication programName];
 #endif
 
-	va_start(arguments, format);
 	msg = [[[OFString alloc] initWithFormat: format
 				      arguments: arguments] autorelease];
-	va_end(arguments);
 
 	[of_stderr writeFormat: @"[%@.%03d %@(%d)] %@\n", dateString,
 				date.microsecond / 1000, me, getpid(), msg];
 
 	objc_autoreleasePoolPop(pool);