diff --git a/libavcodec/idctdsp.c b/libavcodec/idctdsp.c
index 71bd03c606..d07dc29207 100644
--- a/libavcodec/idctdsp.c
+++ b/libavcodec/idctdsp.c
@@ -26,7 +26,7 @@
 #include "simple_idct.h"
 #include "xvididct.h"
 
-av_cold void ff_init_scantable(uint8_t *permutation, ScanTable *st,
+av_cold void ff_init_scantable(const uint8_t *permutation, ScanTable *st,
                                const uint8_t *src_scantable)
 {
     int i, end;
diff --git a/libavcodec/idctdsp.h b/libavcodec/idctdsp.h
index 014488aec3..e8f20acaf2 100644
--- a/libavcodec/idctdsp.h
+++ b/libavcodec/idctdsp.h
@@ -43,7 +43,7 @@ enum idct_permutation_type {
     FF_IDCT_PERM_SSE2,
 };
 
-void ff_init_scantable(uint8_t *permutation, ScanTable *st,
+void ff_init_scantable(const uint8_t *permutation, ScanTable *st,
                        const uint8_t *src_scantable);
 void ff_init_scantable_permutation(uint8_t *idct_permutation,
                                    enum idct_permutation_type perm_type);