diff --git a/src/net/azib/ipscan/core/PortIterator.java b/src/net/azib/ipscan/core/PortIterator.java
index 3a9066b6..c1598a44 100644
--- a/src/net/azib/ipscan/core/PortIterator.java
+++ b/src/net/azib/ipscan/core/PortIterator.java
@@ -96,8 +96,7 @@ public final class PortIterator implements Iterator<Integer>, Cloneable {
 			return (PortIterator) super.clone();
 		}
 		catch (CloneNotSupportedException e) {
-			assert false : "this should never happen";
-			return null;
+			throw new RuntimeException(e);
 		}
 	}
 
diff --git a/src/net/azib/ipscan/exporters/AbstractExporter.java b/src/net/azib/ipscan/exporters/AbstractExporter.java
index 4e235204..364a88bb 100644
--- a/src/net/azib/ipscan/exporters/AbstractExporter.java
+++ b/src/net/azib/ipscan/exporters/AbstractExporter.java
@@ -50,8 +50,7 @@ public abstract class AbstractExporter implements Exporter {
 			return (Exporter) super.clone();
 		}
 		catch (CloneNotSupportedException e) {
-			// this cannot happen
-			return null;
+			throw new RuntimeException(e);
 		}
 	}
 }