diff --git a/include/sgnl/AtomicCondition.h b/include/sgnl/AtomicCondition.h
index 2d2a7f1..ceee138 100644
--- a/include/sgnl/AtomicCondition.h
+++ b/include/sgnl/AtomicCondition.h
@@ -38,7 +38,7 @@ public:
     // This lock is required to avoid a data race between calls to
     // `AtomicCondition::get` when called in `AtomicCondition::wait_*` through
     // a predicate.
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     this->value_.store(val);
   }
 
@@ -61,14 +61,14 @@ public:
   template<typename... Args>
   auto wait(Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait(lock, std::forward<Args>(args)...);
   }
 
   template<typename... Args>
   auto wait_value(ValueType value, Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait(
         lock,
         std::forward<Args>(args)...,
@@ -80,14 +80,14 @@ public:
   template<typename... Args>
   auto wait_for(Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait_for(lock, std::forward<Args>(args)...);
   }
 
   template<typename... Args>
   auto wait_for_value(ValueType value, Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait_for(
         lock,
         std::forward<Args>(args)...,
@@ -99,14 +99,14 @@ public:
   template<typename... Args>
   auto wait_until(Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait_until(lock, std::forward<Args>(args)...);
   }
 
   template<typename... Args>
   auto wait_until_value(ValueType value, Args&&... args) const
   {
-    std::unique_lock lock(this->mutex_);
+    std::unique_lock<std::mutex> lock(this->mutex_);
     return this->condvar_.wait_until(
         lock,
         std::forward<Args>(args)...,
diff --git a/test/test.cpp b/test/test.cpp
index 9e4cf20..9c80f3e 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -264,7 +264,7 @@ TEST_CASE("async_sigwait_handler-condition")
 
 TEST_CASE("constructor-thread-blocks-signals")
 {
-  std::atomic last_signal(0);
+  std::atomic<int> last_signal(0);
   sgnl::SignalHandler signal_handler({SIGTERM, SIGINT});
 
   auto handler = [&last_signal](int signum) {
@@ -297,7 +297,7 @@ TEST_CASE("constructor-thread-blocks-signals")
 TEST_CASE("sleeping-workers-with-exit-condition")
 {
   sgnl::AtomicCondition exit_condition(false);
-  std::initializer_list signals({SIGINT, SIGTERM, SIGUSR1, SIGUSR2});
+  std::initializer_list<int> signals = {SIGINT, SIGTERM, SIGUSR1, SIGUSR2};
   for( auto test_signal : signals )
   {
     exit_condition.set(false);
@@ -338,7 +338,7 @@ TEST_CASE("sleeping-workers-with-exit-condition")
 TEST_CASE("looping-workers-with-exit-condition")
 {
   sgnl::AtomicCondition exit_condition(false);
-  std::initializer_list signals({SIGINT, SIGTERM, SIGUSR1, SIGUSR2});
+  std::initializer_list<int> signals = {SIGINT, SIGTERM, SIGUSR1, SIGUSR2};
   for( auto test_signal : signals )
   {
     exit_condition.set(false);