diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 49e1e55c686a6..762cc88d9fc3d 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -3391,6 +3391,7 @@ static llvm::omp::Directive convertCancellationConstructType(
   case omp::ClauseCancellationConstructType::Taskgroup:
     return llvm::omp::Directive::OMPD_taskgroup;
   }
+  llvm_unreachable("Unhandled cancellation construct type");
 }
 
 static LogicalResult