diff --git a/Userland/Libraries/LibC/mntent.cpp b/Userland/Libraries/LibC/mntent.cpp
index 92df02eb767e42..5874e44bc66328 100644
--- a/Userland/Libraries/LibC/mntent.cpp
+++ b/Userland/Libraries/LibC/mntent.cpp
@@ -16,4 +16,25 @@ struct mntent* getmntent(FILE*)
     TODO();
     return nullptr;
 }
+
+FILE* setmntent(char const*, char const*)
+{
+    dbgln("FIXME: Implement setmntent()");
+    TODO();
+    return nullptr;
+}
+
+int endmntent(FILE*)
+{
+    dbgln("FIXME: Implement endmntent()");
+    TODO();
+    return 0;
+}
+
+struct mntent* getmntent_r(FILE*, struct mntent*, char*, int)
+{
+    dbgln("FIXME: Implement getmntent_r()");
+    TODO();
+    return 0;
+}
 }
diff --git a/Userland/Libraries/LibC/mntent.h b/Userland/Libraries/LibC/mntent.h
index af984d6906b13d..8d51ceab14773b 100644
--- a/Userland/Libraries/LibC/mntent.h
+++ b/Userland/Libraries/LibC/mntent.h
@@ -24,5 +24,8 @@ struct mntent {
 };
 
 struct mntent* getmntent(FILE* stream);
+FILE* setmntent(char const* filename, char const* type);
+int endmntent(FILE* streamp);
+struct mntent* getmntent_r(FILE* streamp, struct mntent* mntbuf, char* buf, int buflen);
 
 __END_DECLS