diff --git a/flang/test/Lower/OpenACC/pre-fir-tree01.f90 b/flang/test/Lower/OpenACC/pre-fir-tree01.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/OpenACC/pre-fir-tree01.f90
@@ -0,0 +1,18 @@
+! RUN: bbc -fopenacc -pft-test -o %t %s | FileCheck %s
+! RUN: %flang_fc1 -fopenacc -fdebug-dump-pft -o %t %s | FileCheck %s
+
+! Test structure of the Pre-FIR tree with OpenACC
+
+subroutine sub1(a, b, n)
+  real :: a(:), b(:)
+  integer :: n, i
+  !$acc parallel loop present(a, b)
+  do i = 1, n
+    b(i) = exp(a(i))
+  end do
+end subroutine
+
+! CHECK-LABEL: Subroutine sub1
+! CHECK:       <<OpenACCConstruct>>
+! CHECK:       <<DoConstruct>>
+! CHECK:       <<End OpenACCConstruct>>
diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
--- a/flang/tools/bbc/bbc.cpp
+++ b/flang/tools/bbc/bbc.cpp
@@ -80,6 +80,10 @@
     llvm::cl::desc("parse the input, create a PFT, dump it, and exit"),
     llvm::cl::init(false));
 
+static llvm::cl::opt<bool> enableOpenACC("fopenacc",
+                                         llvm::cl::desc("enable openacc"),
+                                         llvm::cl::init(false));
+
 #define FLANG_EXCLUDE_CODEGEN
 #include "flang/Tools/CLOptions.inc"
 
@@ -241,6 +245,12 @@
   options.predefinitions.emplace_back(
       "__flang_patchlevel__"s, std::string{FLANG_VERSION_PATCHLEVEL_STRING});
 
+  // enable parsing of OpenACC
+  if (enableOpenACC) {
+    options.features.Enable(Fortran::common::LanguageFeature::OpenACC);
+    options.predefinitions.emplace_back("_OPENACC", "201911");
+  }
+
   Fortran::common::IntrinsicTypeDefaultKinds defaultKinds;
   Fortran::parser::AllSources allSources;
   Fortran::parser::AllCookedSources allCookedSources(allSources);