--- a/cert-to-efi-sig-list.c
+++ b/cert-to-efi-sig-list.c
@@ -6,7 +6,6 @@
 
 
 #include <stdint.h>
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 #ifdef CONFIG_arm
 /* FIXME:
--- a/efi-keytool.c
+++ b/efi-keytool.c
@@ -15,7 +15,6 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 
 #include <kernel_efivars.h>
--- a/efi-readvar.c
+++ b/efi-readvar.c
@@ -17,7 +17,6 @@
 
 #include <openssl/x509.h>
 
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 
 #include <kernel_efivars.h>
--- a/efi-updatevar.c
+++ b/efi-updatevar.c
@@ -20,7 +20,6 @@
 #include <openssl/err.h>
 #include <openssl/pem.h>
 
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 
 #include <kernel_efivars.h>
--- a/flash-var.c
+++ b/flash-var.c
@@ -1,3 +1,5 @@
+#define _XOPEN_SOURCE 700
+
 #include <stdlib.h>
 #include <stdint.h>
 #include <sys/types.h>
@@ -10,7 +12,6 @@
 #include <fcntl.h>
 #include <unistd.h>
 
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 
 #include <version.h>
--- a/hash-to-efi-sig-list.c
+++ b/hash-to-efi-sig-list.c
@@ -4,7 +4,6 @@
  * see COPYING file
  */
 #include <stdint.h>
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 #ifdef CONFIG_arm
 /* FIXME:
--- a/include/variableformat.h
+++ b/include/variableformat.h
@@ -109,7 +109,7 @@
 
 #pragma pack()
 
-inline BOOLEAN
+static inline BOOLEAN
 IsValidVariableHeader (VARIABLE_HEADER   *vh) {
 	if (vh == NULL || vh->StartId != VARIABLE_DATA)
 		return FALSE;
--- a/lib/kernel_efivars.c
+++ b/lib/kernel_efivars.c
@@ -16,7 +16,6 @@
 #include <unistd.h>
 #include <time.h>
 
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 
 #include <kernel_efivars.h>
--- a/sig-list-to-certs.c
+++ b/sig-list-to-certs.c
@@ -4,7 +4,6 @@
  * see COPYING file
  */
 #include <stdint.h>
-#define __STDC_VERSION__ 199901L
 #include <efi.h>
 #ifdef CONFIG_arm
 /* FIXME:
--- a/sign-efi-sig-list.c
+++ b/sign-efi-sig-list.c
@@ -4,7 +4,7 @@
  * see COPYING file
  */
 #include <stdint.h>
-#define __STDC_VERSION__ 199901L
+#define _XOPEN_SOURCE 700
 #include <efi.h>
 #ifdef CONFIG_arm
 /* FIXME: