diff --git a/libweston/color-lcms/color-transform.c b/libweston/color-lcms/color-transform.c
index 3321fa262..15cf3402d 100644
--- a/libweston/color-lcms/color-transform.c
+++ b/libweston/color-lcms/color-transform.c
@@ -1702,13 +1702,13 @@ cmlcms_color_transform_recipe_string(const struct cmlcms_color_transform_recipe
 
 static bool
 build_3d_lut(struct weston_compositor *compositor, cmsHTRANSFORM cmap_3dlut,
-	     unsigned int len_shaper, float *shaper,
+	     unsigned int len_shaper, const float *shaper,
 	     unsigned int len_lut3d, float *lut3d)
 {
 	float divider = len_lut3d - 1;
 	float rgb_in[3], rgb_out[3];
 	uint32_t index, index_r, index_g, index_b;
-	float *curves[3];
+	const float *curves[3];
 
 	curves[0] = &shaper[0];
 	curves[1] = &shaper[len_shaper];
diff --git a/libweston/color.c b/libweston/color.c
index 5fbe403a3..bea061b00 100644
--- a/libweston/color.c
+++ b/libweston/color.c
@@ -430,7 +430,7 @@ linear_interpolation(float x, float x0, float y0, float x1, float y1)
 }
 
 WESTON_EXPORT_FOR_TESTS void
-find_neighbors(struct weston_compositor *compositor, uint32_t len, float *array,
+find_neighbors(struct weston_compositor *compositor, uint32_t len, const float *array,
 	       float val, uint32_t *neigh_A_index, uint32_t *neigh_B_index)
 {
 	bool ascendent = (array[0] <= array[len - 1]);
@@ -469,7 +469,7 @@ find_neighbors(struct weston_compositor *compositor, uint32_t len, float *array,
  */
 WL_EXPORT float
 weston_inverse_evaluate_lut1d(struct weston_compositor *compositor,
-			      uint32_t len_lut, float *lut, float input)
+			      uint32_t len_lut, const float *lut, float input)
 {
 	float divider = len_lut - 1;
 	uint32_t neighbor_A_index, neighbor_B_index;
diff --git a/libweston/color.h b/libweston/color.h
index ac09ae9e1..376782f61 100644
--- a/libweston/color.h
+++ b/libweston/color.h
@@ -681,12 +681,12 @@ weston_color_curve_to_3x1D_LUT(struct weston_compositor *compositor,
 			       size_t lut_size, char **err_msg);
 
 void
-find_neighbors(struct weston_compositor *compositor, uint32_t len, float *array,
+find_neighbors(struct weston_compositor *compositor, uint32_t len, const float *array,
 	       float val, uint32_t *neigh_A_index, uint32_t *neigh_B_index);
 
 float
 weston_inverse_evaluate_lut1d(struct weston_compositor *compositor,
-			      uint32_t len_lut, float *lut, float input);
+			      uint32_t len_lut, const float *lut, float input);
 
 struct weston_color_transform *
 weston_color_transform_ref(struct weston_color_transform *xform);