diff --git a/src/error.F90 b/src/error.F90
index 2eac3f2372..b227f2f588 100644
--- a/src/error.F90
+++ b/src/error.F90
@@ -1,6 +1,6 @@
 module error
 
-  use ISO_FORTRAN_ENV
+  use, intrinsic :: ISO_FORTRAN_ENV
 
   use global, only: master, free_memory, message, mpi_err
 
@@ -63,7 +63,6 @@ contains
        code = -1
     end if
 
-    ! Only allow master to print to screen
     write(ERROR_UNIT, fmt='(1X,A7)', advance='no') 'ERROR: '
 
     n_lines = (len_trim(message)-1)/72 + 1
diff --git a/src/intercycle.F90 b/src/intercycle.F90
index 27d3d10ec0..3ee37a05d2 100644
--- a/src/intercycle.F90
+++ b/src/intercycle.F90
@@ -1,6 +1,6 @@
 module intercycle
 
-  use ISO_FORTRAN_ENV
+  use, intrinsic :: ISO_FORTRAN_ENV
 
   use error,           only: fatal_error, warning
   use global
diff --git a/src/output.F90 b/src/output.F90
index 25cbc94583..1da82f987f 100644
--- a/src/output.F90
+++ b/src/output.F90
@@ -1,6 +1,6 @@
 module output
 
-  use ISO_FORTRAN_ENV
+  use, intrinsic :: ISO_FORTRAN_ENV
 
   use ace_header,      only: Nuclide, Reaction, UrrData
   use constants