diff --git a/platform/darwin/src/MGLAccountManager.m b/platform/darwin/src/MGLAccountManager.m
index 7e55779d0..729caeaa3 100644
--- a/platform/darwin/src/MGLAccountManager.m
+++ b/platform/darwin/src/MGLAccountManager.m
@@ -39,7 +39,7 @@
     }
     static dispatch_once_t onceToken;
     static MGLAccountManager *_sharedManager;
-    void (^setupBlock)() = ^{
+    void (^setupBlock)(void) = ^{
         dispatch_once(&onceToken, ^{
             _sharedManager = [[self alloc] init];
         });
diff --git a/platform/darwin/src/MGLNetworkConfiguration.m b/platform/darwin/src/MGLNetworkConfiguration.m
index 82d333dc9..4cfa405a1 100644
--- a/platform/darwin/src/MGLNetworkConfiguration.m
+++ b/platform/darwin/src/MGLNetworkConfiguration.m
@@ -13,7 +13,7 @@
 + (instancetype)sharedManager {
     static dispatch_once_t onceToken;
     static MGLNetworkConfiguration *_sharedManager;
-    void (^setupBlock)() = ^{
+    void (^setupBlock)(void) = ^{
         dispatch_once(&onceToken, ^{
             _sharedManager = [[self alloc] init];
         });