diff --git a/graph/DelayNormal1.cc b/graph/DelayNormal1.cc
index 1637f282..b8936776 100644
--- a/graph/DelayNormal1.cc
+++ b/graph/DelayNormal1.cc
@@ -351,7 +351,7 @@ operator*(const Delay &delay1,
 	  float delay2)
 {
   return Delay(delay1.mean() * delay2,
-	       delay1.sigma2() * delay2);
+	       delay1.sigma2() * delay2 * delay2);
 }
 
 float
diff --git a/graph/DelayNormal2.cc b/graph/DelayNormal2.cc
index 69eb5bc2..19568eec 100644
--- a/graph/DelayNormal2.cc
+++ b/graph/DelayNormal2.cc
@@ -377,8 +377,8 @@ operator*(const Delay &delay1,
 	  float delay2)
 {
   return Delay(delay1.mean() * delay2,
-	       delay1.sigma2Early() * delay2,
-	       delay1.sigma2Late() * delay2);
+	       delay1.sigma2Early() * delay2 * delay2,
+	       delay1.sigma2Late() * delay2 * delay2);
 }
 
 float