diff --git a/media/libeffects/preprocessing/PreProcessing.cpp b/media/libeffects/preprocessing/PreProcessing.cpp
index 9fd6764..4d94a75 100755
--- a/media/libeffects/preprocessing/PreProcessing.cpp
+++ b/media/libeffects/preprocessing/PreProcessing.cpp
@@ -1072,7 +1072,7 @@
     return sInitStatus;
 }
 
-const effect_descriptor_t *PreProc_GetDescriptor(effect_uuid_t *uuid)
+const effect_descriptor_t *PreProc_GetDescriptor(const effect_uuid_t *uuid)
 {
     size_t i;
     for (i = 0; i < PREPROC_NUM_EFFECTS; i++) {
@@ -1568,7 +1568,7 @@
     return 0;
 }
 
-int PreProcessingLib_Create(effect_uuid_t       *uuid,
+int PreProcessingLib_Create(const effect_uuid_t *uuid,
                             int32_t             sessionId,
                             int32_t             ioId,
                             effect_handle_t  *pInterface)
@@ -1620,7 +1620,7 @@
     return Session_ReleaseEffect(fx->session, fx);
 }
 
-int PreProcessingLib_GetDescriptor(effect_uuid_t       *uuid,
+int PreProcessingLib_GetDescriptor(const effect_uuid_t *uuid,
                                    effect_descriptor_t *pDescriptor) {
 
     if (pDescriptor == NULL || uuid == NULL){