Index: src/OFConstantString.m
==================================================================
--- src/OFConstantString.m
+++ src/OFConstantString.m
@@ -347,10 +347,16 @@
 - (OFString *)stringByAppendingPathComponent: (OFString *)component
 {
 	[self finishInitialization];
 	return [self stringByAppendingPathComponent: component];
 }
+
+- (OFString *)stringByAppendingPathExtension: (OFString *)extension
+{
+	[self finishInitialization];
+	return [self stringByAppendingPathExtension: extension];
+}
 
 - (OFString *)stringByPrependingString: (OFString *)string
 {
 	[self finishInitialization];
 	return [self stringByPrependingString: string];