diff --git a/src/utils/quant_levels_utils.c b/src/utils/quant_levels_utils.c
index 71401647..5c1c767b 100644
--- a/src/utils/quant_levels_utils.c
+++ b/src/utils/quant_levels_utils.c
@@ -30,8 +30,8 @@ WEBP_ASSUME_UNSAFE_INDEXABLE_ABI
 // -----------------------------------------------------------------------------
 // Quantize levels.
 
-int QuantizeLevels(uint8_t* const data, int width, int height, int num_levels,
-                   uint64_t* const sse) {
+int QuantizeLevels(uint8_t* const WEBP_COUNTED_BY((size_t)width* height) data,
+                   int width, int height, int num_levels, uint64_t* const sse) {
   int freq[NUM_SYMBOLS] = {0};
   int q_level[NUM_SYMBOLS] = {0};
   double inv_q_level[NUM_SYMBOLS] = {0};
diff --git a/src/utils/quant_levels_utils.h b/src/utils/quant_levels_utils.h
index 43eecf2a..e2e4486d 100644
--- a/src/utils/quant_levels_utils.h
+++ b/src/utils/quant_levels_utils.h
@@ -29,8 +29,8 @@ extern "C" {
 // quantized values. If not NULL, 'sse' will contain the sum of squared error.
 // Valid range for 'num_levels' is [2, 256].
 // Returns false in case of error (data is NULL, or parameters are invalid).
-int QuantizeLevels(uint8_t* const data, int width, int height, int num_levels,
-                   uint64_t* const sse);
+int QuantizeLevels(uint8_t* const WEBP_COUNTED_BY((size_t)width* height) data,
+                   int width, int height, int num_levels, uint64_t* const sse);
 
 #ifdef __cplusplus
 }  // extern "C"