diff --git a/src/system/kernel/heap.cpp b/src/system/kernel/heap.cpp
index bbf5e81bc0..4201d7ad6b 100644
--- a/src/system/kernel/heap.cpp
+++ b/src/system/kernel/heap.cpp
@@ -100,7 +100,7 @@ static spinlock sDeferredFreeListLock;
 
 // #pragma mark - Tracing
 
-#if KERNEL_HEAP_TRACING
+#ifdef KERNEL_HEAP_TRACING
 namespace KernelHeapTracing {
 
 class Allocate : public AbstractTraceEntry {
diff --git a/src/system/kernel/signal.cpp b/src/system/kernel/signal.cpp
index 3ac7272e74..1bcb584d22 100644
--- a/src/system/kernel/signal.cpp
+++ b/src/system/kernel/signal.cpp
@@ -60,7 +60,7 @@ static status_t deliver_signal(struct thread *thread, uint signal,
 // #pragma mark - signal tracing
 
 
-#if SIGNAL_TRACING
+#ifdef SIGNAL_TRACING
 
 namespace SignalTracing {
 
diff --git a/src/system/kernel/team.cpp b/src/system/kernel/team.cpp
index 6867065d57..7b857b6465 100644
--- a/src/system/kernel/team.cpp
+++ b/src/system/kernel/team.cpp
@@ -88,7 +88,7 @@ spinlock team_spinlock = 0;
 // #pragma mark - Tracing
 
 
-#if TEAM_TRACING
+#ifdef TEAM_TRACING
 namespace TeamTracing {
 
 class TeamForked : public AbstractTraceEntry {