diff --git a/fs_mgr/liblp/images.cpp b/fs_mgr/liblp/images.cpp
index db27022..58a88b5 100644
--- a/fs_mgr/liblp/images.cpp
+++ b/fs_mgr/liblp/images.cpp
@@ -89,8 +89,8 @@
     return true;
 }
 
-bool WriteToImageFile(const char* file, const LpMetadata& input) {
-    unique_fd fd(open(file, O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC, 0644));
+bool WriteToImageFile(const std::string& file, const LpMetadata& input) {
+    unique_fd fd(open(file.c_str(), O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC, 0644));
     if (fd < 0) {
         PERROR << __PRETTY_FUNCTION__ << " open failed: " << file;
         return false;
@@ -149,8 +149,8 @@
     return device_images_.size() == metadata_.block_devices.size();
 }
 
-bool ImageBuilder::Export(const char* file) {
-    unique_fd fd(open(file, O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC, 0644));
+bool ImageBuilder::Export(const std::string& file) {
+    unique_fd fd(open(file.c_str(), O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC, 0644));
     if (fd < 0) {
         PERROR << "open failed: " << file;
         return false;
@@ -438,7 +438,7 @@
     return temp_fds_.back().get();
 }
 
-bool WriteToImageFile(const char* file, const LpMetadata& metadata, uint32_t block_size,
+bool WriteToImageFile(const std::string& file, const LpMetadata& metadata, uint32_t block_size,
                       const std::map<std::string, std::string>& images, bool sparsify) {
     ImageBuilder builder(metadata, block_size, images, sparsify);
     return builder.IsValid() && builder.Build() && builder.Export(file);
diff --git a/fs_mgr/liblp/images.h b/fs_mgr/liblp/images.h
index 75060f9..a284d2e 100644
--- a/fs_mgr/liblp/images.h
+++ b/fs_mgr/liblp/images.h
@@ -41,7 +41,7 @@
                  const std::map<std::string, std::string>& images, bool sparsify);
 
     bool Build();
-    bool Export(const char* file);
+    bool Export(const std::string& file);
     bool ExportFiles(const std::string& dir);
     bool IsValid() const;
 
diff --git a/fs_mgr/liblp/include/liblp/liblp.h b/fs_mgr/liblp/include/liblp/liblp.h
index 5f782b0..d3a7b93 100644
--- a/fs_mgr/liblp/include/liblp/liblp.h
+++ b/fs_mgr/liblp/include/liblp/liblp.h
@@ -72,9 +72,9 @@
 
 // Read/Write logical partition metadata to an image file, for diagnostics or
 // flashing.
-bool WriteToImageFile(const char* file, const LpMetadata& metadata, uint32_t block_size,
+bool WriteToImageFile(const std::string& file, const LpMetadata& metadata, uint32_t block_size,
                       const std::map<std::string, std::string>& images, bool sparsify);
-bool WriteToImageFile(const char* file, const LpMetadata& metadata);
+bool WriteToImageFile(const std::string& file, const LpMetadata& metadata);
 std::unique_ptr<LpMetadata> ReadFromImageFile(const std::string& image_file);
 std::unique_ptr<LpMetadata> ReadFromImageBlob(const void* data, size_t bytes);