diff --git a/src/completion.cc b/src/completion.cc
index a1eed12a..d4e5f04a 100644
--- a/src/completion.cc
+++ b/src/completion.cc
@@ -7,16 +7,18 @@
 namespace Kakoune
 {
 
-CandidateList complete_filename(const std::string& prefix)
+CandidateList complete_filename(const std::string& prefix,
+                                size_t cursor_pos)
 {
-    size_t dir_end = prefix.find_last_of('/');
+    std::string real_prefix = prefix.substr(0, cursor_pos);
+    size_t dir_end = real_prefix.find_last_of('/');
     std::string dirname = "./";
-    std::string fileprefix = prefix;
+    std::string fileprefix = real_prefix;
 
     if (dir_end != std::string::npos)
     {
-        dirname = prefix.substr(0, dir_end + 1);
-        fileprefix = prefix.substr(dir_end + 1, std::string::npos);
+        dirname = real_prefix.substr(0, dir_end + 1);
+        fileprefix = real_prefix.substr(dir_end + 1, std::string::npos);
     }
 
     auto dir = auto_raii(opendir(dirname.c_str()), closedir);
diff --git a/src/completion.hh b/src/completion.hh
index 2607879f..da110638 100644
--- a/src/completion.hh
+++ b/src/completion.hh
@@ -22,7 +22,8 @@ struct Completions
         : start(start), end(end) {}
 };
 
-CandidateList complete_filename(const std::string& prefix);
+CandidateList complete_filename(const std::string& prefix,
+                                size_t cursor_pos = std::string::npos);
 
 }
 #endif // completion_hh_INCLUDED