diff --git a/src/loadRamses.cpp b/src/loadRamses.cpp
index efab10e..8e218d2 100644
--- a/src/loadRamses.cpp
+++ b/src/loadRamses.cpp
@@ -419,7 +419,7 @@ CosmoTool::SimuData *CosmoTool::loadRamsesSimu(const char *basename, int outputI
 	}
       if (flags & NEED_GADGET_ID)
 	{
-	  data->Id = new long[nPar];
+	  data->Id = new int64_t[nPar];
 	}
 
       for (int k = 0; k < 3; k++)