diff --git a/src/libstore/s3-binary-cache-store.cc b/src/libstore/s3-binary-cache-store.cc
index 67935f3ba..1b7dff085 100644
--- a/src/libstore/s3-binary-cache-store.cc
+++ b/src/libstore/s3-binary-cache-store.cc
@@ -343,10 +343,13 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
             std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1)
                 .count();
 
-        printInfo("uploaded 's3://%s/%s' in %d ms",
-            bucketName, path, duration);
+        auto size = istream->tellg();
+
+        printInfo("uploaded 's3://%s/%s' (%d bytes) in %d ms",
+            bucketName, path, size, duration);
 
         stats.putTimeMs += duration;
+        stats.putBytes += size;
         stats.put++;
     }
 
diff --git a/src/libstore/s3-binary-cache-store.hh b/src/libstore/s3-binary-cache-store.hh
index b2b75d498..4d43fe4d2 100644
--- a/src/libstore/s3-binary-cache-store.hh
+++ b/src/libstore/s3-binary-cache-store.hh
@@ -19,6 +19,7 @@ public:
     struct Stats
     {
         std::atomic<uint64_t> put{0};
+        std::atomic<uint64_t> putBytes{0};
         std::atomic<uint64_t> putTimeMs{0};
         std::atomic<uint64_t> get{0};
         std::atomic<uint64_t> getBytes{0};