diff --git a/src/lib.rs b/src/lib.rs
index b7c8826..48fa8a7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -448,6 +448,11 @@ impl Compressor {
     /// It is up to the caller to ensure the provided buffer is large enough to hold
     /// all encoded data.
     pub unsafe fn compress_into(&self, plaintext: &[u8], values: &mut Vec<u8>) {
+        if plaintext.is_empty() {
+            // SAFETY: no data written
+            values.set_len(0);
+            return;
+        }
         let mut in_ptr = plaintext.as_ptr();
         let mut out_ptr = values.as_mut_ptr();