diff --git a/src/sgl/device/helpers.cpp b/src/sgl/device/helpers.cpp
index 3ce2c1da..afc648da 100644
--- a/src/sgl/device/helpers.cpp
+++ b/src/sgl/device/helpers.cpp
@@ -3,9 +3,9 @@
 
 #include "sgl/core/config.h"
 #include "sgl/core/macros.h"
+#include "sgl/core/format.h"
 
 #include <string>
-#include <format>
 
 #if SGL_HAS_D3D12
 #include <dxgidebug.h>
@@ -50,7 +50,7 @@ std::string get_last_gfx_layer_error()
 // used by SLANG_CALL.
 std::string build_slang_failed_message(const char* call, SlangResult result)
 {
-    auto msg = std::format("Slang call {} failed with error: {}\n", call, result);
+    auto msg = fmt::format("Slang call {} failed with error: {}\n", call, result);
     if (static_cast<uint32_t>(result) >= 0x80000000U) {
         std::string gfx_error = get_last_gfx_layer_error();
         if (!gfx_error.empty()) {
diff --git a/src/sgl/device/helpers.h b/src/sgl/device/helpers.h
index d515d029..47e0ad66 100644
--- a/src/sgl/device/helpers.h
+++ b/src/sgl/device/helpers.h
@@ -5,7 +5,6 @@
 #include "sgl/core/error.h"
 
 #include <slang-gfx.h>
-#include <format>
 
 
 namespace sgl {
diff --git a/src/sgl/device/tests/test_hot_reload.cpp b/src/sgl/device/tests/test_hot_reload.cpp
index def3a3f1..022030c8 100644
--- a/src/sgl/device/tests/test_hot_reload.cpp
+++ b/src/sgl/device/tests/test_hot_reload.cpp
@@ -1,13 +1,13 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "testing.h"
+#include "sgl/core/format.h"
 #include "sgl/device/device.h"
 #include "sgl/device/shader.h"
 #include "sgl/device/kernel.h"
 #include "sgl/device/hot_reload.h"
 #include <fstream>
 #include <filesystem>
-#include <format>
 #include <thread>
 #include <chrono>
 
@@ -28,7 +28,7 @@ static void write_shader(const WriteShaderDesc& desc)
         imports += "import " + i + ";\n";
     }
 
-    std::string formatted = std::format(
+    std::string formatted = fmt::format(
         R"SHADER(
 {3}
 RWStructuredBuffer<uint> {0};
@@ -65,7 +65,7 @@ static void write_module(const WriteModuleDesc& desc)
         imports += "import " + i + ";\n";
     }
 
-    std::string formatted = std::format(
+    std::string formatted = fmt::format(
         R"SHADER(
 {0}
 int {1}()