diff --git a/gui/griffon-app/controllers/com/muwire/gui/SignController.groovy b/gui/griffon-app/controllers/com/muwire/gui/SignController.groovy
index bd224773..d73695d0 100644
--- a/gui/griffon-app/controllers/com/muwire/gui/SignController.groovy
+++ b/gui/griffon-app/controllers/com/muwire/gui/SignController.groovy
@@ -29,7 +29,7 @@ class SignController {
     @ControllerAction
     void sign() {
         String plain = view.plainTextArea.getText()
-        byte[] payload = plain.getBytes(StandardCharsets.UTF_8)
+        byte[] payload = plain.trim().getBytes(StandardCharsets.UTF_8)
         def sig = DSAEngine.getInstance().sign(payload, core.spk)
         view.signedTextArea.setText(Base64.encode(sig.data))
     }
diff --git a/webui/src/main/java/com/muwire/webui/SignServlet.java b/webui/src/main/java/com/muwire/webui/SignServlet.java
index dc95e8eb..249e59e5 100644
--- a/webui/src/main/java/com/muwire/webui/SignServlet.java
+++ b/webui/src/main/java/com/muwire/webui/SignServlet.java
@@ -32,7 +32,7 @@ public class SignServlet extends HttpServlet {
             return;
         }
         
-        byte [] payload = text.getBytes(StandardCharsets.UTF_8);
+        byte [] payload = text.trim().getBytes(StandardCharsets.UTF_8);
         Signature sig = DSAEngine.getInstance().sign(payload, core.getSpk());
         
         String response = Base64.encode(sig.getData());