diff --git a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
index 5108469cb6c84ad..908c8fc96f633e2 100644
--- a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
+++ b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
@@ -145,7 +145,7 @@ void AddDebugInfoPass::runOnOperation() {
           subprogramFlags | mlir::LLVM::DISubprogramFlags::Definition;
     }
     unsigned line = 1;
-    if (auto funcLoc = l.dyn_cast<mlir::FileLineColLoc>())
+    if (auto funcLoc = mlir::dyn_cast<mlir::FileLineColLoc>(l))
       line = funcLoc.getLine();
 
     auto spAttr = mlir::LLVM::DISubprogramAttr::get(
diff --git a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
index 0f4ebf9507b1240..227dc978897de71 100644
--- a/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
+++ b/flang/lib/Optimizer/Transforms/DebugTypeGenerator.cpp
@@ -45,10 +45,10 @@ DebugTypeGenerator::convertType(mlir::Type Ty, mlir::LLVM::DIFileAttr fileAttr,
   if (Ty.isInteger()) {
     return genBasicType(context, mlir::StringAttr::get(context, "integer"),
                         Ty.getIntOrFloatBitWidth(), llvm::dwarf::DW_ATE_signed);
-  } else if (Ty.isa<mlir::FloatType>() || Ty.isa<fir::RealType>()) {
+  } else if (mlir::isa<mlir::FloatType>(Ty) || mlir::isa<fir::RealType>(Ty)) {
     return genBasicType(context, mlir::StringAttr::get(context, "real"),
                         Ty.getIntOrFloatBitWidth(), llvm::dwarf::DW_ATE_float);
-  } else if (auto logTy = Ty.dyn_cast_or_null<fir::LogicalType>()) {
+  } else if (auto logTy = mlir::dyn_cast_or_null<fir::LogicalType>(Ty)) {
     return genBasicType(context,
                         mlir::StringAttr::get(context, logTy.getMnemonic()),
                         kindMapping.getLogicalBitsize(logTy.getFKind()),