diff --git a/statistics.c b/statistics.c
index 926b1ee..bc8a096 100755
--- a/statistics.c
+++ b/statistics.c
@@ -42,7 +42,7 @@ radio_float_t SlidingMeanProcess(sl_mean_t *pObj, radio_float_t x)
 	return pObj->mean;
 }
 
-void SlidingMeanProcessV(sl_mean_t *pObj, radio_float_t *pX, uint32_t len)
+void SlidingMeanProcessV(sl_mean_t *pObj, const radio_float_t *pX, uint32_t len)
 {
 	uint32_t i;
 
@@ -102,7 +102,7 @@ radio_float_t SlidingVarProcess(sl_var_t *pObj, radio_float_t x)
 	return pObj->var;
 }
 
-void SlidingVarProcessV(sl_var_t *pObj, radio_float_t *pX, uint32_t len)
+void SlidingVarProcessV(sl_var_t *pObj, const radio_float_t *pX, uint32_t len)
 {
 	uint32_t i;
 
diff --git a/statistics.h b/statistics.h
index c52ad48..f5cc7a2 100755
--- a/statistics.h
+++ b/statistics.h
@@ -59,14 +59,14 @@ extern "C" {
 void SlidingMeanInit(sl_mean_t *pObj, int N);
 void SlidingMeanFree(sl_mean_t *pObj);
 radio_float_t SlidingMeanProcess(sl_mean_t *pObj, radio_float_t x);
-void SlidingMeanProcessV(sl_mean_t *pObj, radio_float_t *pX, uint32_t len);
+void SlidingMeanProcessV(sl_mean_t *pObj, const radio_float_t *pX, uint32_t len);
 radio_float_t SlidingMeanGet(sl_mean_t *pObj);
 
 // Sliding Variance
 void SlidingVarInit(sl_var_t *pObj, int Npwr, int Nmean);
 void SlidingVarFree(sl_var_t *pObj);
 radio_float_t SlidingVarProcess(sl_var_t *pObj, radio_float_t x);
-void SlidingVarProcessV(sl_var_t *pObj, radio_float_t *pX, uint32_t len);
+void SlidingVarProcessV(sl_var_t *pObj, const radio_float_t *pX, uint32_t len);
 radio_float_t SlidingVarGet(sl_var_t *pObj);
 
 // Sliding Min/Max