diff --git a/compat/getprogname.c b/compat/getprogname.c
index 96c2615d2..8b7602a2e 100644
--- a/compat/getprogname.c
+++ b/compat/getprogname.c
@@ -20,7 +20,7 @@
 #include <config.h>
 #include <compat.h>
 
-static char *progname = "sudo";
+static const char *progname = "sudo";
 
 void
 setprogname(const char *name)