diff --git a/src/planner.c b/src/planner.c
index 5494d33..723658a 100644
--- a/src/planner.c
+++ b/src/planner.c
@@ -15,12 +15,14 @@
 #include <string.h>
 #include <time.h>
 
-#define ctime_r(T,Tm) (localtime_s(Tm,T) ? NULL:Tm)
-#define localtime_r(T,Tm) (localtime_s(Tm,T) ? NULL:Tm)
+#ifdef _WIN32
 
+_WIN32 #define ctime_r(T, Tm)(localtime_s(Tm, T) ? NULL : Tm)
+#define localtime_r(T, Tm) (localtime_s(Tm, T) ? NULL : Tm)
+#endif /* ifdef _WIN32 */
 
-const uint intervalLen = 45; // min
-const uint pauseLen = 10;    //
+    const uint intervalLen = 45; // min
+const uint pauseLen = 10;        //
 
 const char taskFormat[] =
     "Task { %.64s = {\n created={%lu},\n deadline={%lu},\n "
diff --git a/src/ui.c b/src/ui.c
index 90417ea..bb0af5f 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -13,8 +13,9 @@
 #include <stdlib.h>
 #include <time.h>
 
-#define localtime_r(T,Tm) (localtime_s(Tm,T) ? NULL:Tm)
-
+#ifdef _WIN32
+#define localtime_r(T, Tm) (localtime_s(Tm, T) ? NULL : Tm)
+#endif
 
 const char *dbName = "db.csv";