diff --git a/source/application/api/use_case/ad/src/AdProcessing.cc b/source/application/api/use_case/ad/src/AdProcessing.cc
index fb26a83..5a85e96 100644
--- a/source/application/api/use_case/ad/src/AdProcessing.cc
+++ b/source/application/api/use_case/ad/src/AdProcessing.cc
@@ -164,7 +164,7 @@
                      size_t cacheSize,
                      float trainingMean)
 {
-    std::function<void (std::vector<int16_t>&, size_t, bool, size_t, size_t)> melSpecFeatureCalc;
+    std::function<void (std::vector<int16_t>&, size_t, bool, size_t, size_t)> melSpecFeatureCalc = nullptr;
 
     TfLiteQuantization quant = inputTensor->quantization;