diff --git a/libavfilter/af_hdcd.c b/libavfilter/af_hdcd.c
index 6f3eb1e875..6b406e7abc 100644
--- a/libavfilter/af_hdcd.c
+++ b/libavfilter/af_hdcd.c
@@ -857,7 +857,7 @@ typedef enum {
     HDCD_PE_PERMANENT    =2
 } hdcd_pe_t;
 
-const char* pe_str[] = {
+static const char * const pe_str[] = {
     "never enabled",
     "enabled intermittently",
     "enabled permanently"