diff --git a/src/Build.h b/src/Build.h
index b033992..0cd34cb 100644
--- a/src/Build.h
+++ b/src/Build.h
@@ -48,7 +48,7 @@ class Build: public ScopedDirective {
     void process_outputs(const File& file);
     void print(std::ostream& stream) const;
 
-    void collect_output_files(std::unordered_set<std::filesystem::path>& output_files) const {outputs.collect_output_files(output_files);}
+    void collect_output_files(std::unordered_set<std::string>& output_files) const {outputs.collect_output_files(output_files);}
 
   private:
     const Rule* rule{};
diff --git a/src/Dependencies.cc b/src/Dependencies.cc
index be02ca2..7b8bddd 100644
--- a/src/Dependencies.cc
+++ b/src/Dependencies.cc
@@ -111,7 +111,7 @@ void Dependencies::serialize(std::ostream& stream) const {
     }
 }
 
-void Dependencies::collect_output_files(std::unordered_set<std::filesystem::path>& output_files) const {
+void Dependencies::collect_output_files(std::unordered_set<std::string>& output_files) const {
     direct.collect_output_files(output_files);
     implicit.collect_output_files(output_files);
     order.collect_output_files(output_files);
diff --git a/src/Dependencies.h b/src/Dependencies.h
index d2be434..3175c31 100644
--- a/src/Dependencies.h
+++ b/src/Dependencies.h
@@ -45,7 +45,7 @@ class Dependencies {
     Dependencies() = default;
 
     void resolve(const Scope& scope);
-    void collect_output_files(std::unordered_set<std::filesystem::path>& output_files) const;
+    void collect_output_files(std::unordered_set<std::string>& output_files) const;
     void mark_as_build();
     void serialize(std::ostream& stream) const;
 
diff --git a/src/File.cc b/src/File.cc
index 01ab9ba..7e1d4eb 100644
--- a/src/File.cc
+++ b/src/File.cc
@@ -59,7 +59,7 @@ File::File(const std::filesystem::path& filename, const std::filesystem::path& b
 
 void File::process() {
     auto bindings = Bindings{};
-    bindings.add(std::shared_ptr<Variable>(new TextVariable{ "command", Text{ std::vector<Word>{ Word{ "fast-ninja", false }, Word{ " ", false }, Word{ source_directory, true } } } }));
+    bindings.add(std::shared_ptr<Variable>(new TextVariable{ "command", Text{ std::vector<Word>{ Word{ "fast-ninja", false }, Word{ " ", false }, Word{ source_directory.string(), true } } } }));
     bindings.add(std::shared_ptr<Variable>(new TextVariable{ "generator", Text{ "1", false } }));
 
     rules["fast-ninja"] = Rule(this, "fast-ninja", bindings);
diff --git a/src/File.h b/src/File.h
index bbe1c19..c5e1151 100644
--- a/src/File.h
+++ b/src/File.h
@@ -53,7 +53,7 @@ class File: public Scope {
     explicit File(const std::filesystem::path& filename, const std::filesystem::path& build_directory = ".", const File* next = {});
 
     void process();
-    [[nodiscard]] bool is_output(const std::filesystem::path& file) const {return outputs.contains(file.lexically_normal());}
+    [[nodiscard]] bool is_output(const std::filesystem::path& file) const {return outputs.contains(file.lexically_normal().string());}
     [[nodiscard]] const Rule* find_rule(const std::string& name) const;
     [[nodiscard]] const Variable* find_variable(const std::string& name) const;
 
@@ -82,7 +82,7 @@ class File: public Scope {
     std::filesystem::path source_filename;
     std::filesystem::path build_filename;
 
-    std::unordered_set<std::filesystem::path> outputs;
+    std::unordered_set<std::string> outputs;
     std::set<std::string> includes;
     std::map<std::string, Rule> rules;
     std::map<std::string, Pool> pools;
diff --git a/src/FilenameList.cc b/src/FilenameList.cc
index 6dce1c9..d36c4f8 100644
--- a/src/FilenameList.cc
+++ b/src/FilenameList.cc
@@ -115,10 +115,10 @@ std::ostream& operator<<(std::ostream& stream, const FilenameList& filename_list
     return stream;
 }
 
-void FilenameList::collect_output_files(std::unordered_set<std::filesystem::path>& output_files) const {
+void FilenameList::collect_output_files(std::unordered_set<std::string>& output_files) const {
     for (auto& filename: filenames) {
         if (filename.type == Filename::Type::BUILD) {
-            output_files.insert(filename.full_name());
+            output_files.insert(filename.full_name().string());
         }
     }
 }
diff --git a/src/FilenameList.h b/src/FilenameList.h
index 91fd3bd..1174e1a 100644
--- a/src/FilenameList.h
+++ b/src/FilenameList.h
@@ -53,7 +53,7 @@ class FilenameList {
     [[nodiscard]] bool empty() const {return words.empty() && filenames.empty();}
     void serialize(std::ostream& stream) const;
     [[nodiscard]] std::string string() const;
-    void collect_output_files(std::unordered_set<std::filesystem::path>& output_files) const;
+    void collect_output_files(std::unordered_set<std::string>& output_files) const;
 
     void collect_filenames(std::vector<Filename>& collector) const {collector.insert(collector.end(), filenames.begin(), filenames.end());}
 
diff --git a/src/FilenameWord.h b/src/FilenameWord.h
index cf6e93a..442fdcc 100644
--- a/src/FilenameWord.h
+++ b/src/FilenameWord.h
@@ -35,6 +35,7 @@ IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "Filename.h"
 
 #include <variant>
+#include <vector>
 
 #include "VariableReference.h"