diff --git a/vp9/encoder/vp9_onyx_if.c b/vp9/encoder/vp9_onyx_if.c
index 04c742f0a33ddffc0f02205ba2ff06da82964c41..5a9403fd313c726b39b6a1d86bbea177a0b2a508 100644
--- a/vp9/encoder/vp9_onyx_if.c
+++ b/vp9/encoder/vp9_onyx_if.c
@@ -41,6 +41,9 @@
 #include "vp9/encoder/vp9_rdopt.h"
 #include "vp9/encoder/vp9_segmentation.h"
 #include "vp9/encoder/vp9_speed_features.h"
+#if CONFIG_INTERNAL_STATS
+#include "vp9/encoder/vp9_ssim.h"
+#endif
 #include "vp9/encoder/vp9_temporal_filter.h"
 #include "vp9/encoder/vp9_resize.h"
 #include "vp9/encoder/vp9_svc_layercontext.h"
@@ -63,19 +66,6 @@ void vp9_coef_tree_initialize();
 #define MAX_MB_RATE 250
 #define MAXRATE_1080P 2025000
 
-#if CONFIG_INTERNAL_STATS
-extern double vp9_calc_ssim(YV12_BUFFER_CONFIG *source,
-                            YV12_BUFFER_CONFIG *dest, int lumamask,
-                            double *weight);
-
-
-extern double vp9_calc_ssimg(YV12_BUFFER_CONFIG *source,
-                             YV12_BUFFER_CONFIG *dest, double *ssim_y,
-                             double *ssim_u, double *ssim_v);
-
-
-#endif
-
 // #define OUTPUT_YUV_REC
 
 #ifdef OUTPUT_YUV_SRC
diff --git a/vp9/encoder/vp9_ssim.c b/vp9/encoder/vp9_ssim.c
index 1435191d026979e0a2d868bb31ec99d0d1bf324f..026e6a8fd9df018d3684da0664c1ec3c02c7322a 100644
--- a/vp9/encoder/vp9_ssim.c
+++ b/vp9/encoder/vp9_ssim.c
@@ -8,8 +8,9 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include "./vp9_rtcd.h"
 
-#include "vp9/encoder/vp9_onyx_int.h"
+#include "vp9/encoder/vp9_ssim.h"
 
 void vp9_ssim_parms_16x16_c(uint8_t *s, int sp, uint8_t *r,
                             int rp, unsigned long *sum_s, unsigned long *sum_r,
diff --git a/vp9/encoder/vp9_ssim.h b/vp9/encoder/vp9_ssim.h
new file mode 100644
index 0000000000000000000000000000000000000000..a581c2c23d4869624e0f08c85249f38f6f777df7
--- /dev/null
+++ b/vp9/encoder/vp9_ssim.h
@@ -0,0 +1,30 @@
+/*
+ *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VP9_ENCODER_VP9_SSIM_H_
+#define VP9_ENCODER_VP9_SSIM_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "vpx_scale/yv12config.h"
+
+double vp9_calc_ssim(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest,
+                     int lumamask, double *weight);
+
+double vp9_calc_ssimg(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest,
+                      double *ssim_y, double *ssim_u, double *ssim_v);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VP9_ENCODER_VP9_SSIM_H_
diff --git a/vp9/vp9cx.mk b/vp9/vp9cx.mk
index 21a388e5140f2f69414a7d684201d4c5fa982c4a..da6c0f8b6ef2720fd2761c43fc76d13816255aff 100644
--- a/vp9/vp9cx.mk
+++ b/vp9/vp9cx.mk
@@ -68,6 +68,7 @@ VP9_CX_SRCS-yes += encoder/vp9_svc_layercontext.c
 VP9_CX_SRCS-yes += encoder/vp9_resize.c
 VP9_CX_SRCS-yes += encoder/vp9_resize.h
 VP9_CX_SRCS-$(CONFIG_INTERNAL_STATS) += encoder/vp9_ssim.c
+VP9_CX_SRCS-$(CONFIG_INTERNAL_STATS) += encoder/vp9_ssim.h
 VP9_CX_SRCS-yes += encoder/vp9_tokenize.c
 VP9_CX_SRCS-yes += encoder/vp9_treewriter.c
 VP9_CX_SRCS-yes += encoder/vp9_variance.c