diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index 1cfe1cd..09a91e0 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -31,7 +31,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #define mbedtls_printf          printf
-#define MBEDTLS_EXTI_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
 #endif /* MBEDTLS_PLATFORM_C */