diff --git a/mlir/lib/Conversion/OpenMPToLLVM/OpenMPToLLVM.cpp b/mlir/lib/Conversion/OpenMPToLLVM/OpenMPToLLVM.cpp
--- a/mlir/lib/Conversion/OpenMPToLLVM/OpenMPToLLVM.cpp
+++ b/mlir/lib/Conversion/OpenMPToLLVM/OpenMPToLLVM.cpp
@@ -81,13 +81,14 @@
 
 void mlir::configureOpenMPToLLVMConversionLegality(
     ConversionTarget &target, LLVMTypeConverter &typeConverter) {
-  target.addDynamicallyLegalOp<mlir::omp::ParallelOp, mlir::omp::WsLoopOp,
-                               mlir::omp::MasterOp, mlir::omp::SectionsOp,
-                               mlir::omp::SingleOp>([&](Operation *op) {
-    return typeConverter.isLegal(&op->getRegion(0)) &&
-           typeConverter.isLegal(op->getOperandTypes()) &&
-           typeConverter.isLegal(op->getResultTypes());
-  });
+  target.addDynamicallyLegalOp<mlir::omp::CriticalOp, mlir::omp::ParallelOp,
+                               mlir::omp::WsLoopOp, mlir::omp::MasterOp,
+                               mlir::omp::SectionsOp, mlir::omp::SingleOp>(
+      [&](Operation *op) {
+        return typeConverter.isLegal(&op->getRegion(0)) &&
+               typeConverter.isLegal(op->getOperandTypes()) &&
+               typeConverter.isLegal(op->getResultTypes());
+      });
   target
       .addDynamicallyLegalOp<mlir::omp::AtomicReadOp, mlir::omp::AtomicWriteOp,
                              mlir::omp::FlushOp, mlir::omp::ThreadprivateOp>(
@@ -100,9 +101,9 @@
 void mlir::populateOpenMPToLLVMConversionPatterns(LLVMTypeConverter &converter,
                                                   RewritePatternSet &patterns) {
   patterns.add<
-      RegionOpConversion<omp::MasterOp>, RegionOpConversion<omp::ParallelOp>,
-      RegionOpConversion<omp::WsLoopOp>, RegionOpConversion<omp::SectionsOp>,
-      RegionOpConversion<omp::SingleOp>,
+      RegionOpConversion<omp::CriticalOp>, RegionOpConversion<omp::MasterOp>,
+      RegionOpConversion<omp::ParallelOp>, RegionOpConversion<omp::WsLoopOp>,
+      RegionOpConversion<omp::SectionsOp>, RegionOpConversion<omp::SingleOp>,
       RegionLessOpWithVarOperandsConversion<omp::AtomicReadOp>,
       RegionLessOpWithVarOperandsConversion<omp::AtomicWriteOp>,
       RegionLessOpWithVarOperandsConversion<omp::FlushOp>,
diff --git a/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir b/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
--- a/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
+++ b/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
@@ -1,5 +1,23 @@
 // RUN: mlir-opt -convert-openmp-to-llvm -split-input-file %s | FileCheck %s
 
+// CHECK-LABEL: llvm.func @foo(i64, i64)
+func.func private @foo(index, index)
+
+// CHECK-LABEL: llvm.func @critical_block_arg
+func.func @critical_block_arg() {
+  // CHECK: omp.critical
+  omp.critical {
+  // CHECK-NEXT: ^[[BB0:.*]](%[[ARG1:.*]]: i64, %[[ARG2:.*]]: i64):
+  ^bb0(%arg1: index, %arg2: index):
+    // CHECK-NEXT: llvm.call @foo(%[[ARG1]], %[[ARG2]]) : (i64, i64) -> ()
+    func.call @foo(%arg1, %arg2) : (index, index) -> ()
+    omp.terminator
+  }
+  return
+}
+
+// -----
+
 // CHECK-LABEL: llvm.func @master_block_arg
 func.func @master_block_arg() {
   // CHECK: omp.master