diff --git Makefile.PL.old Makefile.PL
index 37eca8e..02d4a34 100644
--- Makefile.PL.old
+++ Makefile.PL
@@ -45,7 +45,7 @@ sub cflags {
     my @cflags = split /\n/, $cflags;
 
     $self->{CCFLAGS} .= ' -Wall';     # Flag all warnings
-    $self->{CCFLAGS} .= ' -std=c89';  # Compile according to C99 standard
+    $self->{CCFLAGS} .= ' -std=c99';  # Compile according to C99 standard
 
     foreach (@cflags) {
         $_ = "CCFLAGS = $self->{CCFLAGS}" if /^CCFLAGS/;