diff --git a/src/core/osutils.cc b/src/core/osutils.cc
index f023a465..2647c26c 100644
--- a/src/core/osutils.cc
+++ b/src/core/osutils.cc
@@ -769,6 +769,7 @@ string decimalkilos(unsigned long long value)
   }
 
   out << value;
+  out << " ";
   if ((i > 0) && (i <= strlen(prefixes)))
     out << prefixes[i - 1];