diff --git a/vpx_dsp/vpx_dsp_rtcd_defs.pl b/vpx_dsp/vpx_dsp_rtcd_defs.pl
index ae544eb64986f16b381851a0691783e8dc72dd76..68380f9a5ded57062ba2a6246b84c0ed14a87adb 100644
--- a/vpx_dsp/vpx_dsp_rtcd_defs.pl
+++ b/vpx_dsp/vpx_dsp_rtcd_defs.pl
@@ -1209,7 +1209,7 @@ if (vpx_config("CONFIG_VP9_HIGHBITDEPTH") eq "yes") {
   # Structured Similarity (SSIM)
   #
   if (vpx_config("CONFIG_INTERNAL_STATS") eq "yes") {
-    add_proto qw/void vpx_highbd_ssim_parms_8x8/, "uint16_t *s, int sp, uint16_t *r, int rp, uint32_t *sum_s, uint32_t *sum_r, uint32_t *sum_sq_s, uint32_t *sum_sq_r, uint32_t *sum_sxr";
+    add_proto qw/void vpx_highbd_ssim_parms_8x8/, "const uint16_t *s, int sp, const uint16_t *r, int rp, uint32_t *sum_s, uint32_t *sum_r, uint32_t *sum_sq_s, uint32_t *sum_sq_r, uint32_t *sum_sxr";
     specialize qw/vpx_highbd_ssim_parms_8x8/;
   }
 }  # CONFIG_VP9_HIGHBITDEPTH