diff --git a/mlir/lib/TableGen/Interfaces.cpp b/mlir/lib/TableGen/Interfaces.cpp
--- a/mlir/lib/TableGen/Interfaces.cpp
+++ b/mlir/lib/TableGen/Interfaces.cpp
@@ -9,6 +9,7 @@
 #include "mlir/TableGen/Interfaces.h"
 #include "llvm/ADT/FunctionExtras.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringSet.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
@@ -83,6 +84,8 @@
   // Initialize the interface base classes.
   auto *basesInit =
       dyn_cast<llvm::ListInit>(def->getValueInit("baseInterfaces"));
+  // Chained inheritance will produce duplicates in the base interface set.
+  StringSet<> basesAdded;
   llvm::unique_function<void(Interface)> addBaseInterfaceFn =
       [&](const Interface &baseInterface) {
         // Inherit any base interfaces.
@@ -90,7 +93,10 @@
           addBaseInterfaceFn(baseBaseInterface);
 
         // Add the base interface.
+        if (basesAdded.contains(baseInterface.getName()))
+          return;
         baseInterfaces.push_back(std::make_unique<Interface>(baseInterface));
+        basesAdded.insert(baseInterface.getName());
       };
   for (llvm::Init *init : basesInit->getValues())
     addBaseInterfaceFn(Interface(cast<llvm::DefInit>(init)->getDef()));
diff --git a/mlir/test/mlir-tblgen/op-interface.td b/mlir/test/mlir-tblgen/op-interface.td
--- a/mlir/test/mlir-tblgen/op-interface.td
+++ b/mlir/test/mlir-tblgen/op-interface.td
@@ -34,7 +34,18 @@
 // DECL-NEXT:   return (*static_cast<ConcreteOp *>(this)).someOtherMethod();
 // DECL-NEXT: }
 
-def TestInheritanceBaseInterface : OpInterface<"TestInheritanceBaseInterface"> {
+def TestInheritanceMultiBaseInterface : OpInterface<"TestInheritanceMultiBaseInterface"> {
+  let methods = [
+    InterfaceMethod<
+      /*desc=*/[{some function comment}],
+      /*retTy=*/"int",
+      /*methodName=*/"baz",
+      /*args=*/(ins "int":$input)
+    >
+  ];
+}
+
+def TestInheritanceBaseInterface : OpInterface<"TestInheritanceBaseInterface", [TestInheritanceMultiBaseInterface]> {
   let methods = [
     InterfaceMethod<
       /*desc=*/[{some function comment}],
@@ -60,6 +71,8 @@
 
 // DECL: class TestInheritanceZDerivedInterface
 // DECL: struct Concept {
+// DECL:     const TestInheritanceMultiBaseInterface::Concept *implTestInheritanceMultiBaseInterface = nullptr;
+// DECL-NOT: const TestInheritanceMultiBaseInterface::Concept
 // DECL:     const TestInheritanceBaseInterface::Concept *implTestInheritanceBaseInterface = nullptr;
 // DECL:     const TestInheritanceMiddleBaseInterface::Concept *implTestInheritanceMiddleBaseInterface = nullptr;