diff --git a/Userland/Libraries/LibC/fcntl.cpp b/Userland/Libraries/LibC/fcntl.cpp
index 7927845678e..8a8ab0f11f2 100644
--- a/Userland/Libraries/LibC/fcntl.cpp
+++ b/Userland/Libraries/LibC/fcntl.cpp
@@ -117,7 +117,7 @@ int posix_fadvise(int fd, off_t offset, off_t len, int advice)
 int posix_fallocate(int fd, off_t offset, off_t len)
 {
     // posix_fallocate does not set errno.
-    return static_cast<int>(syscall(SC_posix_fallocate, fd, &offset, &len));
+    return -static_cast<int>(syscall(SC_posix_fallocate, fd, &offset, &len));
 }
 
 // https://pubs.opengroup.org/onlinepubs/9699919799/functions/utimensat.html