diff --git a/libraries/AP_HAL_Linux/Util.cpp b/libraries/AP_HAL_Linux/Util.cpp
index bfceab6dcd..d25bc87a3d 100644
--- a/libraries/AP_HAL_Linux/Util.cpp
+++ b/libraries/AP_HAL_Linux/Util.cpp
@@ -241,7 +241,7 @@ int Util::get_hw_arm32()
     return -ENOENT;
 }
 
-#ifdef ENABLE_HEAP
+#if ENABLE_HEAP
 void *Util::allocate_heap_memory(size_t size)
 {
     struct heap *new_heap = (struct heap*)malloc(sizeof(struct heap));
diff --git a/libraries/AP_HAL_Linux/Util.h b/libraries/AP_HAL_Linux/Util.h
index 70faada85b..11a29dacb3 100644
--- a/libraries/AP_HAL_Linux/Util.h
+++ b/libraries/AP_HAL_Linux/Util.h
@@ -71,7 +71,7 @@ public:
     bool get_system_id(char buf[50]) override;
     bool get_system_id_unformatted(uint8_t buf[], uint8_t &len) override;
 
-#ifdef ENABLE_HEAP
+#if ENABLE_HEAP
     // heap functions, note that a heap once alloc'd cannot be dealloc'd
     virtual void *allocate_heap_memory(size_t size) override;
     virtual void *heap_realloc(void *h, void *ptr, size_t old_size, size_t new_size) override;
@@ -116,7 +116,7 @@ private:
     const char *custom_defaults = HAL_PARAM_DEFAULTS_PATH;
     static const char *_hw_names[UTIL_NUM_HARDWARES];
 
-#ifdef ENABLE_HEAP
+#if ENABLE_HEAP
     struct heap_allocation_header {
         size_t allocation_size; // size of allocated block, not including this header
     };