diff --git a/src/ML-PACE/pair_pace_extrapolation.cpp b/src/ML-PACE/pair_pace_extrapolation.cpp
index 907609b90f..26de937ddb 100644
--- a/src/ML-PACE/pair_pace_extrapolation.cpp
+++ b/src/ML-PACE/pair_pace_extrapolation.cpp
@@ -215,8 +215,8 @@ void PairPACEExtrapolation::compute(int eflag, int vflag)
     // 'compute_atom' will update the `ace->e_atom` and `ace->neighbours_forces(jj, alpha)` arrays and max_gamma_grade
 
     if (flag_compute_extrapolation_grade) {
-      extrapolation_grade_gamma[i] = aceimpl->ace->max_gamma_grade;
-      ;
+      //FIXME: need an updated PACE library URL since this currently fails compiling
+      // extrapolation_grade_gamma[i] = aceimpl->ace->max_gamma_grade;
     }
 
     Array2D<DOUBLE_TYPE> &neighbours_forces =