Index: flang/tools/f18/flang
===================================================================
--- flang/tools/f18/flang
+++ flang/tools/f18/flang
@@ -180,7 +180,9 @@
 #   * the Flang driver (either new or the "throwaway" driver)
 #   * the external Fortran driver that will generate the code
 # Most options accepted by Flang will be claimed by it. The only exceptions are
-# `-I` and `-J`.
+# `-I`, `-J`, `-fopenmp` and `-fopenacc` which are passed to both compilers
+# and `-acc` which is replaced with `-fopenacc` for compatibility with
+# external nvfortran compiler.
 #
 # INPUTS:
 #   $1 - all compiler options (array, name reference)
@@ -256,6 +258,11 @@
       [[ $opt == "-fopenacc" ]]; then
       flang_opts+=($opt)
       fc_opts+=($opt)
+    elif
+      # Options that have different names in Flang and the external driver.
+      [[ $opt == "-acc" ]]; then
+      flang_opts+=("-fopenacc")
+      fc_opts+=($opt)
     else
       # All other options are claimed for the external driver.
       fc_opts+=($opt)