diff --git a/hls4ml/templates/vivado/nnet_utils/nnet_mult.h b/hls4ml/templates/vivado/nnet_utils/nnet_mult.h
index 0de1c5a24..6a91ad431 100644
--- a/hls4ml/templates/vivado/nnet_utils/nnet_mult.h
+++ b/hls4ml/templates/vivado/nnet_utils/nnet_mult.h
@@ -90,13 +90,13 @@ class weight_exponential : public Product<x_T, w_T, y_T>{
 
 template<class data_T, class res_T, typename CONFIG_T>
 inline typename std::enable_if<std::is_same<data_T, ap_uint<1>>::value
-        and std::is_same<typename CONFIG_T::weight_t, ap_uint<1>>::value, ap_int<nnet::ceillog2(CONFIG_T::n_in) + 2>>::type
+        && std::is_same<typename CONFIG_T::weight_t, ap_uint<1>>::value, ap_int<nnet::ceillog2(CONFIG_T::n_in) + 2>>::type
 cast(typename CONFIG_T::accum_t x){
   return (ap_int<nnet::ceillog2(CONFIG_T::n_in) + 2>) (x - CONFIG_T::n_in / 2) * 2;
 }
 
 template<class data_T, class res_T, typename CONFIG_T>
-inline typename std::enable_if<(not std::is_same<data_T, ap_uint<1>>::value), res_T>::type
+inline typename std::enable_if<(! std::is_same<data_T, ap_uint<1>>::value), res_T>::type
 cast(typename CONFIG_T::accum_t x){
   return (res_T) x;
 }