diff --git a/branches/ParadisEO-GPU/src/GPUType/moGPUVector.h b/branches/ParadisEO-GPU/src/GPUType/moGPUVector.h
index deb99600b..c918c5e88 100644
--- a/branches/ParadisEO-GPU/src/GPUType/moGPUVector.h
+++ b/branches/ParadisEO-GPU/src/GPUType/moGPUVector.h
@@ -172,7 +172,7 @@ public:
 	 * @param _os A std::ostream.
 	 */
 
-	virtual void printOn(std::ostream& os) const=0;
+	virtual void printOn(std::ostream& _os) const=0;
 
 protected: