diff --git a/src/nvim/memory.h b/src/nvim/memory.h
index f65947d449..250ac3e08f 100644
--- a/src/nvim/memory.h
+++ b/src/nvim/memory.h
@@ -1,9 +1,10 @@
 #ifndef NVIM_MEMORY_H
 #define NVIM_MEMORY_H
 
+#include <stdbool.h>  // for bool
 #include <stdint.h>  // for uint8_t
 #include <stddef.h>  // for size_t
-#include <time.h>    // for time_t
+#include <time.h>  // for time_t
 
 /// `malloc()` function signature
 typedef void *(*MemMalloc)(size_t);
diff --git a/test/unit/preprocess.lua b/test/unit/preprocess.lua
index 8c2a5c73e5..1c9b290462 100644
--- a/test/unit/preprocess.lua
+++ b/test/unit/preprocess.lua
@@ -123,6 +123,7 @@ function Gcc:init_defines()
   self:define('INIT', {'...'}, '')
   self:define('_GNU_SOURCE')
   self:define('INCLUDE_GENERATED_DECLARATIONS')
+  self:define('UNIT_TESTING')
   -- Needed for FreeBSD
   self:define('_Thread_local', nil, '')
   -- Needed for macOS Sierra