diff --git a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
--- a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
+++ b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
@@ -12,9 +12,12 @@
 mlir_tablegen(FIROps.cpp.inc -gen-op-defs)
 mlir_tablegen(FIROpsTypes.h.inc --gen-typedef-decls)
 mlir_tablegen(FIROpsTypes.cpp.inc --gen-typedef-defs)
-add_mlir_interface(FortranVariableInterface)
 add_public_tablegen_target(FIROpsIncGen)
 
+set(LLVM_TARGET_DEFINITIONS FortranVariableInterface.td)
+mlir_tablegen(FortranVariableInterface.h.inc -gen-op-interface-decls)
+mlir_tablegen(FortranVariableInterface.cpp.inc -gen-op-interface-defs)
+
 set(LLVM_TARGET_DEFINITIONS CanonicalizationPatterns.td)
 mlir_tablegen(CanonicalizationPatterns.inc -gen-rewriters)
 add_public_tablegen_target(CanonicalizationPatternsIncGen)