diff --git a/src/main/java/org/cactoos/io/TeeInputStream.java b/src/main/java/org/cactoos/io/TeeInputStream.java
index bd31b29de9..c882476354 100644
--- a/src/main/java/org/cactoos/io/TeeInputStream.java
+++ b/src/main/java/org/cactoos/io/TeeInputStream.java
@@ -59,7 +59,9 @@ public TeeInputStream(final InputStream src, final OutputStream tgt) {
     @Override
     public int read() throws IOException {
         final int data = this.input.read();
-        this.output.write(data);
+        if (data >= 0) {
+            this.output.write(data);
+        }
         return data;
     }