diff --git a/Kernel/FileDescriptor.cpp b/Kernel/FileDescriptor.cpp
index 5aea6d181f8..42e144cc1e5 100644
--- a/Kernel/FileDescriptor.cpp
+++ b/Kernel/FileDescriptor.cpp
@@ -278,8 +278,9 @@ ssize_t FileDescriptor::get_dir_entries(byte* buffer, ssize_t size)
     if (!metadata.is_directory())
         return -ENOTDIR;
 
-    // FIXME: Compute the actual size needed.
-    auto temp_buffer = ByteBuffer::create_uninitialized(2048);
+    int size_to_allocate = max(PAGE_SIZE, metadata.size);
+
+    auto temp_buffer = ByteBuffer::create_uninitialized(size_to_allocate);
     BufferStream stream(temp_buffer);
     VFS::the().traverse_directory_inode(*m_inode, [&stream] (auto& entry) {
         stream << (dword)entry.inode.index();
@@ -288,11 +289,12 @@ ssize_t FileDescriptor::get_dir_entries(byte* buffer, ssize_t size)
         stream << entry.name;
         return true;
     });
+    stream.snip();
 
-    if (size < stream.offset())
+    if (size < temp_buffer.size())
         return -1;
 
-    memcpy(buffer, temp_buffer.pointer(), stream.offset());
+    memcpy(buffer, temp_buffer.pointer(), temp_buffer.size());
     return stream.offset();
 }
 
diff --git a/LibC/dirent.cpp b/LibC/dirent.cpp
index ef1ec33bc21..f9c8d33db1b 100644
--- a/LibC/dirent.cpp
+++ b/LibC/dirent.cpp
@@ -5,6 +5,9 @@
 #include <string.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <AK/StdLibExtras.h>
 #include <Kernel/Syscall.h>
 
 extern "C" {
@@ -54,9 +57,13 @@ dirent* readdir(DIR* dirp)
         return nullptr;
 
     if (!dirp->buffer) {
-        // FIXME: Figure out how much to actually allocate.
-        dirp->buffer = (char*)malloc(4096);
-        ssize_t nread = syscall(SC_get_dir_entries, dirp->fd, dirp->buffer, 4096);
+        struct stat st;
+        int rc = fstat(dirp->fd, &st);
+        if (rc < 0)
+            return nullptr;
+        size_t size_to_allocate = max(st.st_size, 4096);
+        dirp->buffer = (char*)malloc(size_to_allocate);
+        ssize_t nread = syscall(SC_get_dir_entries, dirp->fd, dirp->buffer, size_to_allocate);
         dirp->buffer_size = nread;
         dirp->nextptr = dirp->buffer;
     }