diff --git a/system/ulib/fit/sequencer.cpp b/system/ulib/fit/sequencer.cpp
index 35c60d38601036cd25ef9d18047d16b3c2206a24..687db6737be3e7aa10f1297ed6e7dbe87d775def 100644
--- a/system/ulib/fit/sequencer.cpp
+++ b/system/ulib/fit/sequencer.cpp
@@ -20,7 +20,7 @@ sequencer::sequencer() {
 sequencer::~sequencer() = default;
 
 fit::consumer<> sequencer::swap_prior(fit::consumer<> new_prior) {
-    std::lock_guard lock(mutex_);
+    std::lock_guard<std::mutex> lock(mutex_);
     fit::consumer<> old_prior = std::move(prior_);
     prior_ = std::move(new_prior);
     return old_prior;