diff --git a/src/dawn/wire/server/ServerAdapter.cpp b/src/dawn/wire/server/ServerAdapter.cpp
index a1df75bb31..8a6901e489 100644
--- a/src/dawn/wire/server/ServerAdapter.cpp
+++ b/src/dawn/wire/server/ServerAdapter.cpp
@@ -93,7 +93,7 @@ namespace dawn::wire::server {
             }
         }
 
-        cmd.featuresCount = features.size();
+        cmd.featuresCount = static_cast<uint32_t>(features.size());
         cmd.features = features.data();
 
         WGPUSupportedLimits limits = {};
diff --git a/src/dawn/wire/server/ServerInstance.cpp b/src/dawn/wire/server/ServerInstance.cpp
index 529bb48b77..10998008b5 100644
--- a/src/dawn/wire/server/ServerInstance.cpp
+++ b/src/dawn/wire/server/ServerInstance.cpp
@@ -86,7 +86,7 @@ namespace dawn::wire::server {
         // Hide features the wire cannot support.
         auto it = std::partition(features.begin(), features.end(), IsFeatureSupported);
 
-        cmd.featuresCount = std::distance(features.begin(), it);
+        cmd.featuresCount = static_cast<uint32_t>(std::distance(features.begin(), it));
         cmd.features = features.data();
 
         mProcs.adapterGetProperties(adapter, &properties);