diff --git a/src/main/java/org/takes/rq/RqLengthAware.java b/src/main/java/org/takes/rq/RqLengthAware.java
index 0436b0d74..b204da547 100644
--- a/src/main/java/org/takes/rq/RqLengthAware.java
+++ b/src/main/java/org/takes/rq/RqLengthAware.java
@@ -52,7 +52,9 @@
 @EqualsAndHashCode(callSuper = true)
 public final class RqLengthAware extends RqWrap {
 
-    /**
+    private static final String CONTENT_LENGTH = "Content-Length";
+
+	/**
      * Ctor.
      * @param req Original request
      */
@@ -68,14 +70,16 @@ public RqLengthAware(final Request req) {
      */
     private static InputStream cap(final Request req) throws IOException {
         final Iterator<String> hdr = new RqHeaders.Base(req)
-            .header("Content-Length").iterator();
-        InputStream body = req.body();
-        long length = (long) body.available();
-        if (hdr.hasNext()) {
-            length = Long.parseLong(hdr.next());
-        }
-        body = new CapInputStream(body, length);
-        return body;
+            .header(CONTENT_LENGTH).iterator();
+		if(hdr.hasNext()) {
+			String value = hdr.next();
+			try {
+				return new CapInputStream(req.body(), Long.parseLong(value));
+			} catch(NumberFormatException e) {
+				throw new IOException(String.format("Invalid %s header: %s", CONTENT_LENGTH, value));
+			}
+		}
+        return req.body();
     }
 
 }
diff --git a/src/test/java/org/takes/rq/RqLengthAwareTest.java b/src/test/java/org/takes/rq/RqLengthAwareTest.java
index 4fe943c8f..34c600ce3 100644
--- a/src/test/java/org/takes/rq/RqLengthAwareTest.java
+++ b/src/test/java/org/takes/rq/RqLengthAwareTest.java
@@ -23,9 +23,12 @@
  */
 package org.takes.rq;
 
+import java.io.ByteArrayInputStream;
+import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
+
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Test;
@@ -95,6 +98,34 @@ void readsByte() throws IOException {
             Matchers.equalTo(data.length() - 1)
         );
     }
+    
+    @Test
+    void noContentLength() throws IOException {
+        byte[] bytes = "test".getBytes();
+		final InputStream data = new FilterInputStream(new ByteArrayInputStream(bytes)) {
+        	@Override
+        	public int available() throws IOException {
+        		//This simulates a stream where only one byte is available at once
+        		return 1;
+        	}
+        };
+        final InputStream stream = new RqLengthAware(
+            new RqFake(
+                Arrays.asList(
+                    "GET /test1",
+                    "Host: b.example.com"
+                    //We have no content length header so RqLengthAware should simply do nothing
+                ),
+                data
+            )
+        ).body();
+        for(int i = 0; i < bytes.length; i++) {
+        	MatcherAssert.assertThat(
+        			stream.read(),
+        			Matchers.equalTo(bytes[i] & 0xFF)
+        			);
+		}
+    }
 
     @Test
     void readsByteArray() throws IOException {