diff --git a/Userland/Libraries/LibC/wchar.cpp b/Userland/Libraries/LibC/wchar.cpp
index 1445aea761..b26b2d1c13 100644
--- a/Userland/Libraries/LibC/wchar.cpp
+++ b/Userland/Libraries/LibC/wchar.cpp
@@ -441,4 +441,10 @@ double wcstod(const wchar_t*, wchar_t**)
     dbgln("TODO: Implement wcstod()");
     TODO();
 }
+
+long double wcstold(const wchar_t*, wchar_t**)
+{
+    dbgln("TODO: Implement wcstold()");
+    TODO();
+}
 }
diff --git a/Userland/Libraries/LibC/wchar.h b/Userland/Libraries/LibC/wchar.h
index 2e4a769be0..fd92663f80 100644
--- a/Userland/Libraries/LibC/wchar.h
+++ b/Userland/Libraries/LibC/wchar.h
@@ -51,5 +51,6 @@ unsigned long wcstoul(const wchar_t*, wchar_t**, int);
 unsigned long long wcstoull(const wchar_t*, wchar_t**, int);
 float wcstof(const wchar_t*, wchar_t**);
 double wcstod(const wchar_t*, wchar_t**);
+long double wcstold(const wchar_t*, wchar_t**);
 
 __END_DECLS