diff --git a/library/x509.c b/library/x509.c
index 68cc022..bd0d69a 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -962,7 +962,7 @@
     return( 0 );
 }
 
-int mbedtls_x509_time_expired( const mbedtls_x509_time *to )
+int mbedtls_x509_time_is_past( const mbedtls_x509_time *to )
 {
     mbedtls_x509_time now;
 
@@ -972,7 +972,7 @@
     return( x509_check_time( &now, to ) );
 }
 
-int mbedtls_x509_time_future( const mbedtls_x509_time *from )
+int mbedtls_x509_time_is_future( const mbedtls_x509_time *from )
 {
     mbedtls_x509_time now;
 
@@ -984,13 +984,13 @@
 
 #else  /* MBEDTLS_HAVE_TIME */
 
-int mbedtls_x509_time_expired( const mbedtls_x509_time *to )
+int mbedtls_x509_time_is_past( const mbedtls_x509_time *to )
 {
     ((void) to);
     return( 0 );
 }
 
-int mbedtls_x509_time_future( const mbedtls_x509_time *from )
+int mbedtls_x509_time_is_future( const mbedtls_x509_time *from )
 {
     ((void) from);
     return( 0 );