diff --git a/NVEncCore/convert_csp.cpp b/NVEncCore/convert_csp.cpp
index 6d89296d..6459a417 100644
--- a/NVEncCore/convert_csp.cpp
+++ b/NVEncCore/convert_csp.cpp
@@ -2449,7 +2449,7 @@ const ConvertCSP *get_convert_csp_func(RGY_CSP csp_from, RGY_CSP csp_to, bool uv
     return convert;
 }
 
-const funcConvertCSP get_copy_alpha_func(RGY_CSP csp_from, RGY_CSP csp_to) {
+funcConvertCSP get_copy_alpha_func(RGY_CSP csp_from, RGY_CSP csp_to) {
     const auto csp_base_from = rgy_csp_alpha_base(csp_from);
     const auto csp_base_to = rgy_csp_alpha_base(csp_to);
     if (csp_base_from != RGY_CSP_NA && csp_base_to != RGY_CSP_NA) {
diff --git a/NVEncCore/convert_csp.h b/NVEncCore/convert_csp.h
index af71b55d..1c14e3a0 100644
--- a/NVEncCore/convert_csp.h
+++ b/NVEncCore/convert_csp.h
@@ -708,7 +708,7 @@ typedef struct ConvertCSP {
 } ConvertCSP;
 
 const ConvertCSP *get_convert_csp_func(RGY_CSP csp_from, RGY_CSP csp_to, bool uv_only, RGY_SIMD simd);
-const funcConvertCSP get_copy_alpha_func(RGY_CSP csp_from, RGY_CSP csp_to);
+funcConvertCSP get_copy_alpha_func(RGY_CSP csp_from, RGY_CSP csp_to);
 const TCHAR *get_simd_str(RGY_SIMD simd);
 
 enum RGY_FRAME_FLAGS : uint32_t {