diff --git a/programs/datagen.c b/programs/datagen.c
index 389b5dbc..0b3dce2e 100644
--- a/programs/datagen.c
+++ b/programs/datagen.c
@@ -23,6 +23,12 @@
     - source repository : https://github.com/Cyan4973/zstd
 */
 
+/* *************************************
+*  Compiler Options
+***************************************/
+#define _CRT_SECURE_NO_WARNINGS  /* removes Visual warning on strerror() */
+
+
 /*-************************************
 *  Includes
 **************************************/
diff --git a/programs/fileio.c b/programs/fileio.c
index 20fc82db..5b41ec0f 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -41,7 +41,8 @@
 /* *************************************
 *  Compiler Options
 ***************************************/
-#define _POSIX_SOURCE 1        /* enable %llu on Windows */
+#define _POSIX_SOURCE 1          /* enable %llu on Windows */
+#define _CRT_SECURE_NO_WARNINGS  /* removes Visual warning on strerror() */
 
 
 /*-*************************************