diff --git a/onert-micro/onert-micro/include/pal/common/PALElu.h b/onert-micro/onert-micro/include/pal/common/PALElu.h
index fdb46098b15..a5687562eed 100644
--- a/onert-micro/onert-micro/include/pal/common/PALElu.h
+++ b/onert-micro/onert-micro/include/pal/common/PALElu.h
@@ -34,7 +34,7 @@ inline OMStatus Elu(const int flat_size, const float *input_data, float *output_
   for (int i = 0; i < flat_size; i++)
   {
     float val = input_data[i];
-    float result = val < 0.0f ? std::expm1(val) : val;
+    float result = val < 0.0f ? std::exp(val) - 1 : val;
     output_data[i] = result;
   }
 
diff --git a/onert-micro/onert-micro/include/pal/common/PALSVDFCommon.h b/onert-micro/onert-micro/include/pal/common/PALSVDFCommon.h
index 673d389299f..f396a63635f 100644
--- a/onert-micro/onert-micro/include/pal/common/PALSVDFCommon.h
+++ b/onert-micro/onert-micro/include/pal/common/PALSVDFCommon.h
@@ -49,7 +49,7 @@ inline float activationValFloat(const circle::ActivationFunctionType act, float
     case circle::ActivationFunctionType_TANH:
       return std::tanh(a);
     case circle::ActivationFunctionType_SIGN_BIT:
-      return std::signbit(a);
+      return (a < 0) ? true : false;
     default:
       assert(false && "Not supported");
   }