diff --git a/src/relax/backend/vm/codegen_vm.cc b/src/relax/backend/vm/codegen_vm.cc
index 13dc02fde4a1..bf29556768c5 100644
--- a/src/relax/backend/vm/codegen_vm.cc
+++ b/src/relax/backend/vm/codegen_vm.cc
@@ -465,30 +465,20 @@ void LinkModules(ObjectPtr<VMExecutable> exec, const ffi::Map<ffi::String, runti
                  const tvm::ffi::Module& lib, const ffi::Array<ffi::Module>& ext_libs) {
   // query if we need const loader for ext_modules
   // Wrap all submodules in the initialization wrapper.
-  std::unordered_map<std::string, std::vector<std::string>> const_vars_by_symbol;
+  ffi::Map<ffi::String, ffi::Array<ffi::String>> const_vars_by_symbol;
   for (tvm::ffi::Module mod : ext_libs) {
     auto pf_sym = mod->GetFunction("get_symbol");
     auto pf_var = mod->GetFunction("get_const_vars");
-    std::vector<std::string> symbol_const_vars;
     if (pf_sym.has_value() && pf_var.has_value()) {
       ffi::String symbol = (*pf_sym)().cast<ffi::String>();
       ffi::Array<ffi::String> variables = (*pf_var)().cast<ffi::Array<ffi::String>>();
-      for (size_t i = 0; i < variables.size(); i++) {
-        symbol_const_vars.push_back(variables[i].operator std::string());
-      }
-      TVM_FFI_ICHECK_EQ(const_vars_by_symbol.count(symbol), 0U)
-          << "Found duplicated symbol: " << symbol;
-      const_vars_by_symbol[symbol] = symbol_const_vars;
+      TVM_FFI_ICHECK(!const_vars_by_symbol.count(symbol)) << "Found duplicated symbol: " << symbol;
+      const_vars_by_symbol.Set(symbol, variables);
     }
   }
   if (!const_vars_by_symbol.empty() || !params.empty()) {
     // need runtime const information, run link const loader
-    std::unordered_map<std::string, runtime::Tensor> const_var_tensor;
-    for (const auto& [name, param] : params) {
-      const_var_tensor[name] = param;
-    }
-    ffi::Module const_loader_mod =
-        runtime::ConstLoaderModuleCreate(const_var_tensor, const_vars_by_symbol);
+    ffi::Module const_loader_mod = runtime::ConstLoaderModuleCreate(params, const_vars_by_symbol);
     const_loader_mod->ImportModule(lib);
     for (const auto& it : ext_libs) {
       const_loader_mod->ImportModule(it);
diff --git a/src/runtime/const_loader_module.cc b/src/runtime/const_loader_module.cc
index 006c1f1e1acd..aaaeb9737e2d 100644
--- a/src/runtime/const_loader_module.cc
+++ b/src/runtime/const_loader_module.cc
@@ -39,6 +39,9 @@
 #include <tvm/support/io.h>
 
 #include <cstdint>
+#include <string>
+#include <unordered_map>
+#include <vector>
 
 #include "../support/bytes_io.h"
 
diff --git a/src/runtime/const_loader_module.h b/src/runtime/const_loader_module.h
index c97232016d8a..6722785cc950 100644
--- a/src/runtime/const_loader_module.h
+++ b/src/runtime/const_loader_module.h
@@ -29,13 +29,10 @@
 #include <tvm/ffi/container/map.h>
 #include <tvm/ffi/extra/module.h>
 #include <tvm/ffi/function.h>
+#include <tvm/ffi/string.h>
 #include <tvm/runtime/base.h>
 #include <tvm/runtime/tensor.h>
 
-#include <string>
-#include <unordered_map>
-#include <vector>
-
 namespace tvm {
 namespace runtime {
 
@@ -52,26 +49,13 @@ namespace runtime {
  * The creator is always available (ConstLoaderModule is a runtime-universal module).
  */
 inline ffi::Module ConstLoaderModuleCreate(
-    const std::unordered_map<std::string, Tensor>& const_var_tensor,
-    const std::unordered_map<std::string, std::vector<std::string>>& const_vars_by_symbol) {
+    const ffi::Map<ffi::String, Tensor>& const_var_tensor,
+    const ffi::Map<ffi::String, ffi::Array<ffi::String>>& const_vars_by_symbol) {
   static const auto fcreate = ffi::Function::GetGlobal("ffi.Module.create.const_loader");
   TVM_FFI_CHECK(fcreate.has_value(), RuntimeError)
       << "ffi.Module.create.const_loader is not registered in runtime. "
       << "Ensure libtvm_runtime is loaded.";
-  // Convert to FFI-compatible types.
-  ffi::Map<ffi::String, Tensor> ffi_const_var_tensor;
-  for (const auto& kv : const_var_tensor) {
-    ffi_const_var_tensor.Set(kv.first, kv.second);
-  }
-  ffi::Map<ffi::String, ffi::Array<ffi::String>> ffi_const_vars_by_symbol;
-  for (const auto& kv : const_vars_by_symbol) {
-    ffi::Array<ffi::String> vars;
-    for (const auto& v : kv.second) {
-      vars.push_back(ffi::String(v));
-    }
-    ffi_const_vars_by_symbol.Set(kv.first, vars);
-  }
-  return (*fcreate)(ffi_const_var_tensor, ffi_const_vars_by_symbol).cast<ffi::Module>();
+  return (*fcreate)(const_var_tensor, const_vars_by_symbol).cast<ffi::Module>();
 }
 
 }  // namespace runtime
diff --git a/src/runtime/metal/metal_module.h b/src/runtime/metal/metal_module.h
index fe9454f674d1..3f4b3965adc5 100644
--- a/src/runtime/metal/metal_module.h
+++ b/src/runtime/metal/metal_module.h
@@ -28,11 +28,6 @@
 #include <tvm/ffi/extra/module.h>
 #include <tvm/ffi/function.h>
 
-#include <memory>
-#include <string>
-#include <unordered_map>
-#include <vector>
-
 #include "../metadata.h"
 
 namespace tvm {
diff --git a/src/runtime/opencl/opencl_module.h b/src/runtime/opencl/opencl_module.h
index 6697badd4885..9d16ea9231b2 100644
--- a/src/runtime/opencl/opencl_module.h
+++ b/src/runtime/opencl/opencl_module.h
@@ -28,10 +28,8 @@
 #include <tvm/ffi/function.h>
 #include <tvm/runtime/base.h>
 
-#include <memory>
 #include <string>
 #include <unordered_map>
-#include <vector>
 
 #include "../../support/bytes_io.h"
 #include "../metadata.h"
@@ -74,7 +72,7 @@ inline ffi::Module OpenCLModuleCreate(ffi::String data, ffi::String fmt,
  */
 inline ffi::Module OpenCLModuleCreate(
     const std::unordered_map<std::string, spirv::SPIRVShader>& shaders,
-    const std::string& spirv_text, ffi::Map<ffi::String, FunctionInfo> fmap) {
+    const ffi::String& spirv_text, const ffi::Map<ffi::String, FunctionInfo>& fmap) {
   static const auto fcreate = ffi::Function::GetGlobal("ffi.Module.create.opencl.spirv");
   TVM_FFI_CHECK(fcreate.has_value(), RuntimeError)
       << "ffi.Module.create.opencl.spirv is not registered in runtime. "
@@ -87,7 +85,7 @@ inline ffi::Module OpenCLModuleCreate(
     strm.Write(kv.second);
     shader_bytes.Set(kv.first, ffi::Bytes(std::move(buf)));
   }
-  return (*fcreate)(shader_bytes, ffi::String(spirv_text), fmap).cast<ffi::Module>();
+  return (*fcreate)(shader_bytes, spirv_text, fmap).cast<ffi::Module>();
 }
 }  // namespace runtime
 }  // namespace tvm
diff --git a/src/runtime/vulkan/vulkan_module.h b/src/runtime/vulkan/vulkan_module.h
index 87df473753d4..d8fdda4d9251 100644
--- a/src/runtime/vulkan/vulkan_module.h
+++ b/src/runtime/vulkan/vulkan_module.h
@@ -48,9 +48,9 @@ namespace vulkan {
  * and rehydrated on the runtime side.
  * Requires libtvm_runtime built with USE_VULKAN=ON to have registered the creator.
  */
-inline ffi::Module VulkanModuleCreate(std::unordered_map<std::string, SPIRVShader> smap,
-                                      ffi::Map<ffi::String, FunctionInfo> fmap,
-                                      std::string source) {
+inline ffi::Module VulkanModuleCreate(const std::unordered_map<std::string, SPIRVShader>& smap,
+                                      const ffi::Map<ffi::String, FunctionInfo>& fmap,
+                                      const ffi::String& source) {
   static const auto fcreate = ffi::Function::GetGlobal("ffi.Module.create.vulkan");
   TVM_FFI_CHECK(fcreate.has_value(), RuntimeError)
       << "ffi.Module.create.vulkan is not registered in runtime. "
@@ -63,7 +63,7 @@ inline ffi::Module VulkanModuleCreate(std::unordered_map<std::string, SPIRVShade
     strm.Write(kv.second);
     shader_bytes.Set(kv.first, ffi::Bytes(std::move(buf)));
   }
-  return (*fcreate)(shader_bytes, fmap, ffi::String(source)).cast<ffi::Module>();
+  return (*fcreate)(shader_bytes, fmap, source).cast<ffi::Module>();
 }
 
 }  // namespace vulkan