diff --git a/Code/Learning/otbSVMModel.txx b/Code/Learning/otbSVMModel.txx
index 59766b00b01a682689751ca5a2640b9d026d3f99..75dfa15c49105f151078adf3fb967395055ca99a 100644
--- a/Code/Learning/otbSVMModel.txx
+++ b/Code/Learning/otbSVMModel.txx
@@ -85,7 +85,7 @@ SVMModel<TInputPixel, TLabel>
     delete [] m_XSpace;
     m_XSpace = new struct svm_node[elements];
 
-    for(unsigned int i = 0;i<elements;++i)
+    for(long int i = 0;i<elements;++i)
       {
 	m_XSpace[i].value = 0;
 	m_XSpace[i].index = -1;