diff --git a/MacPass/NSString+MPPasswordCreation.m b/MacPass/NSString+MPPasswordCreation.m
index a834e8e7..20b3b3c1 100644
--- a/MacPass/NSString+MPPasswordCreation.m
+++ b/MacPass/NSString+MPPasswordCreation.m
@@ -26,7 +26,7 @@
 #import "NSString+MPComposedCharacterAdditions.h"
 #import "MPSettingsHelper.h"
 
-static NSDictionary<NSNumber *, NSString *> *characterClassMap () {
+static NSDictionary<NSNumber *, NSString *> *characterClassMap (void) {
   static dispatch_once_t onceToken;
   static NSDictionary *characterClassMap;
   dispatch_once(&onceToken, ^{