diff --git a/flang/lib/Lower/OpenMP.cpp b/flang/lib/Lower/OpenMP.cpp
--- a/flang/lib/Lower/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP.cpp
@@ -173,6 +173,12 @@
     }
   }
 
+  for (auto *ps : privatizedSymbols) {
+    if (ps->has<Fortran::semantics::CommonBlockDetails>())
+      TODO(converter.getCurrentLocation(),
+           "Common Block in privatization clause");
+  }
+
   if (hasCollapse && hasLastPrivateOp)
     TODO(converter.getCurrentLocation(), "Collapse clause with lastprivate");
 }
diff --git a/flang/test/Lower/OpenMP/Todo/firstprivate-commonblock.f90 b/flang/test/Lower/OpenMP/Todo/firstprivate-commonblock.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/firstprivate-commonblock.f90
@@ -0,0 +1,10 @@
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+
+! CHECK: not yet implemented: Common Block in privatization clause
+subroutine firstprivate_common
+  common /c/ x, y
+  real x, y
+  !$omp parallel firstprivate(/c/)
+  !$omp end parallel
+end subroutine
diff --git a/flang/test/Lower/OpenMP/Todo/lastprivate-commonblock.f90 b/flang/test/Lower/OpenMP/Todo/lastprivate-commonblock.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/lastprivate-commonblock.f90
@@ -0,0 +1,12 @@
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+
+! CHECK: not yet implemented: Common Block in privatization clause
+subroutine lastprivate_common
+  common /c/ x, y
+  real x, y
+  !$omp do lastprivate(/c/)
+  do i=1,100
+  end do
+  !$omp end do
+end subroutine
diff --git a/flang/test/Lower/OpenMP/Todo/private-commonblock.f90 b/flang/test/Lower/OpenMP/Todo/private-commonblock.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/private-commonblock.f90
@@ -0,0 +1,10 @@
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+
+! CHECK: not yet implemented: Common Block in privatization clause
+subroutine private_common
+  common /c/ x, y
+  real x, y
+  !$omp parallel private(/c/)
+  !$omp end parallel
+end subroutine