diff --git a/plugins/common/plugin/NativeHelpers.cpp b/plugins/common/plugin/NativeHelpers.cpp
index 8300fffa..d9517fb6 100644
--- a/plugins/common/plugin/NativeHelpers.cpp
+++ b/plugins/common/plugin/NativeHelpers.cpp
@@ -14,10 +14,11 @@
 
 
 #if defined(_WIN32)
-const fs::path toPlatformAgnosticPath(std::string& filePath)
+const fs::path toPlatformAgnosticPath(const std::string& filePath)
 {
-    std::replace(filePath.begin(), filePath.end(), '\\', '/');
-    return fs::u8path(filePath);
+    std::string p { filePath };
+    std::replace(p.begin(), p.end(), '\\', '/');
+    return fs::u8path(p);
 }
 const fs::path fromPlatformAgnosticPath(const char *filePath)
 {
@@ -26,7 +27,7 @@ const fs::path fromPlatformAgnosticPath(const char *filePath)
     return fs::u8path(p);
 }
 #else
-const fs::path toPlatformAgnosticPath(std::string& filePath)
+const fs::path toPlatformAgnosticPath(const std::string& filePath)
 {
     return fs::u8path(filePath);
 }
diff --git a/plugins/common/plugin/NativeHelpers.h b/plugins/common/plugin/NativeHelpers.h
index d031dcb2..3bac9d33 100644
--- a/plugins/common/plugin/NativeHelpers.h
+++ b/plugins/common/plugin/NativeHelpers.h
@@ -13,7 +13,7 @@
 
 const fs::path& getUserDocumentsDirectory();
 
-const fs::path toPlatformAgnosticPath(std::string& filePath);
+const fs::path toPlatformAgnosticPath(const std::string& filePath);
 const fs::path fromPlatformAgnosticPath(const char *filePath);
 
 #if !defined(_WIN32) && !defined(__APPLE__)
diff --git a/plugins/vst/SfizzVstState.cpp b/plugins/vst/SfizzVstState.cpp
index 11080156..e31064f5 100644
--- a/plugins/vst/SfizzVstState.cpp
+++ b/plugins/vst/SfizzVstState.cpp
@@ -122,7 +122,7 @@ tresult SfizzVstState::store(IBStream* state) const
     if (!s.writeInt64u(currentStateVersion))
         return kResultFalse;
 
-    if (!s.writeStr8(sfzFile.c_str()))
+    if (!s.writeStr8(toPlatformAgnosticPath(sfzFile).string().c_str()))
         return kResultFalse;
 
     if (!s.writeFloat(volume))
@@ -137,7 +137,7 @@ tresult SfizzVstState::store(IBStream* state) const
     if (!s.writeInt32(preloadSize))
         return kResultFalse;
 
-    if (!s.writeStr8(scalaFile.c_str()))
+    if (!s.writeStr8(toPlatformAgnosticPath(scalaFile).string().c_str()))
         return kResultFalse;
 
     if (!s.writeInt32(scalaRootKey))