diff --git a/src/smt/smt_quantifier.cpp b/src/smt/smt_quantifier.cpp
index 8fd0e08bc..e9b0e069a 100644
--- a/src/smt/smt_quantifier.cpp
+++ b/src/smt/smt_quantifier.cpp
@@ -439,12 +439,12 @@ namespace smt {
         virtual bool model_based() const { return m_fparams->m_mbqi; }
 
         virtual bool mbqi_enabled(quantifier *q) const { 
-	  if(!m_fparams->m_mbqi_id) return true;
-	  const symbol &s = q->get_qid();
-	  unsigned len = strlen(m_fparams->m_mbqi_id);
-	  if(s == symbol::null || s.is_numerical())
-	    return len == 0;
-	  return strncmp(s.bare_str(),m_fparams->m_mbqi_id,len) == 0;
+            if(!m_fparams->m_mbqi_id) return true;
+            const symbol &s = q->get_qid();
+            size_t len = strlen(m_fparams->m_mbqi_id);
+            if(s == symbol::null || s.is_numerical())
+                return len == 0;
+            return strncmp(s.bare_str(),m_fparams->m_mbqi_id,len) == 0;
 	}
 
       /* Quantifier id's must begin with the prefix specified by