diff --git a/lfs.c b/lfs.c
index 194d0f8..3f13fd6 100644
--- a/lfs.c
+++ b/lfs.c
@@ -1377,6 +1377,11 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
         }
     }
 
+    if (file->pos >= file->size) {
+        // eof if past end
+        return 0;
+    }
+
     size = lfs_min(size, file->size - file->pos);
     nsize = size;
 
@@ -1432,6 +1437,19 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
         file->pos = file->size;
     }
 
+    if (!(file->flags & LFS_F_WRITING) && file->pos > file->size) {
+        // fill with zeros
+        lfs_off_t pos = file->pos;
+        file->pos = file->size;
+
+        while (file->pos < pos) {
+            lfs_ssize_t res = lfs_file_write(lfs, file, &(uint8_t){0}, 1);
+            if (res < 0) {
+                return res;
+            }
+        }
+    }
+
     while (nsize > 0) {
         // check if we need a new block
         if (!(file->flags & LFS_F_WRITING) ||
@@ -1506,8 +1524,16 @@ lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
     if (whence == LFS_SEEK_SET) {
         file->pos = off;
     } else if (whence == LFS_SEEK_CUR) {
+        if (-off > file->pos) {
+            return LFS_ERR_INVAL;
+        }
+
         file->pos = file->pos + off;
     } else if (whence == LFS_SEEK_END) {
+        if (-off > file->size) {
+            return LFS_ERR_INVAL;
+        }
+
         file->pos = file->size + off;
     }
 
diff --git a/tests/test_seek.sh b/tests/test_seek.sh
index 1f70ee3..8b90928 100755
--- a/tests/test_seek.sh
+++ b/tests/test_seek.sh
@@ -305,5 +305,43 @@ tests/test.py << TEST
     lfs_unmount(&lfs) => 0;
 TEST
 
+echo "--- Out-of-bounds seek ---"
+tests/test.py << TEST
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file[0], "hello/kitty42", LFS_O_RDWR) => 0;
+
+    size = strlen("kittycatcat");
+    lfs_file_size(&lfs, &file[0]) => $LARGESIZE*size;
+    lfs_file_seek(&lfs, &file[0],
+            ($LARGESIZE+$SMALLSIZE)*size, LFS_SEEK_SET) => 0;
+    lfs_file_read(&lfs, &file[0], buffer, size) => 0;
+
+    memcpy(buffer, "porcupineee", size);
+    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+
+    lfs_file_seek(&lfs, &file[0],
+            ($LARGESIZE+$SMALLSIZE)*size, LFS_SEEK_SET) =>
+            ($LARGESIZE+$SMALLSIZE+1)*size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "porcupineee", size) => 0;
+
+    lfs_file_seek(&lfs, &file[0],
+            $LARGESIZE*size, LFS_SEEK_SET) =>
+            ($LARGESIZE+$SMALLSIZE+1)*size;
+    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    memcmp(buffer, "\0\0\0\0\0\0\0\0\0\0\0", size) => 0;
+
+    lfs_file_seek(&lfs, &file[0],
+            -(($LARGESIZE+$SMALLSIZE)*size), LFS_SEEK_CUR) => LFS_ERR_INVAL;
+    lfs_file_tell(&lfs, &file[0]) => ($LARGESIZE+1)*size;
+
+    lfs_file_seek(&lfs, &file[0],
+            -(($LARGESIZE+2*$SMALLSIZE)*size), LFS_SEEK_END) => LFS_ERR_INVAL;
+    lfs_file_tell(&lfs, &file[0]) => ($LARGESIZE+1)*size;
+
+    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs_unmount(&lfs) => 0;
+TEST
+
 echo "--- Results ---"
 tests/stats.py