diff --git a/src/modules/fs.cpp b/src/modules/fs.cpp
index a8e6f8ea..44b87cd1 100644
--- a/src/modules/fs.cpp
+++ b/src/modules/fs.cpp
@@ -96,10 +96,11 @@ namespace modules {
         mount->type = details->at(MOUNTINFO_TYPE);
         mount->fsname = details->at(MOUNTINFO_FSNAME);
 
-        mount->bytes_total = buffer.f_bsize * buffer.f_blocks;
+        // see: http://en.cppreference.com/w/cpp/filesystem/space
+        mount->bytes_total = buffer.f_frsize * buffer.f_blocks;
         mount->bytes_free = buffer.f_bsize * buffer.f_bfree;
         mount->bytes_used = mount->bytes_total - mount->bytes_free;
-        mount->bytes_avail = buffer.f_bsize * buffer.f_bavail;
+        mount->bytes_avail = buffer.f_frsize * buffer.f_bavail;
 
         mount->percentage_free = math_util::percentage<double>(mount->bytes_avail, mount->bytes_used + mount->bytes_avail);
         mount->percentage_used = math_util::percentage<double>(mount->bytes_used, mount->bytes_used + mount->bytes_avail);