diff --git a/sortix/directory.cpp b/sortix/directory.cpp
index e37f9598..664d1a31 100644
--- a/sortix/directory.cpp
+++ b/sortix/directory.cpp
@@ -81,6 +81,7 @@ namespace Sortix
 				// another one (provide as many as we can).
 				prev = dirent;
 				size_t bytesused = sizeof(sortix_dirent) + dirent->d_namelen + 1;
+				ASSERT(bytesused <= size);
 				size -= bytesused;
 				dirent = (sortix_dirent*) ( ((byte*) dirent) + bytesused );
 			}
diff --git a/sortix/fs/devfs.cpp b/sortix/fs/devfs.cpp
index bf24018e..3fcf9f9f 100644
--- a/sortix/fs/devfs.cpp
+++ b/sortix/fs/devfs.cpp
@@ -318,7 +318,7 @@ namespace Sortix
 		{
 			dirent->d_namelen = needed;
 			Error::Set(ERANGE);
-			return 0;
+			return -1;
 		}
 
 		Memory::Copy(dirent->d_name, name, namelen + 1);
diff --git a/sortix/fs/initfs.cpp b/sortix/fs/initfs.cpp
index 1cf74921..ed05a853 100644
--- a/sortix/fs/initfs.cpp
+++ b/sortix/fs/initfs.cpp
@@ -185,7 +185,7 @@ namespace Sortix
 		{
 			dirent->d_namelen = needed;
 			Error::Set(ERANGE);
-			return 0;
+			return -1;
 		}
 
 		Memory::Copy(dirent->d_name, name, namelen + 1);
diff --git a/sortix/fs/ramfs.cpp b/sortix/fs/ramfs.cpp
index 15d39419..283a6fe8 100644
--- a/sortix/fs/ramfs.cpp
+++ b/sortix/fs/ramfs.cpp
@@ -223,7 +223,7 @@ namespace Sortix
 		{
 			dirent->d_namelen = needed;
 			Error::Set(ERANGE);
-			return 0;
+			return -1;
 		}
 
 		Memory::Copy(dirent->d_name, name, namelen + 1);