diff --git a/src/impala/matrix.c b/src/impala/matrix.c
index 8afed8d..b103dd3 100644
--- a/src/impala/matrix.c
+++ b/src/impala/matrix.c
@@ -1503,18 +1503,18 @@ dim mclxUnaryList
 mclv* mclgUnionv
 (  mclx* mx
 ,  const mclv* coldom
-,  const mclv* restrict
+,  const mclv* parm_restrict
 ,  mcxenum scratch_STATUS
 ,  mclv* dst
 )
-   {  return mclgUnionv2(mx, coldom, restrict, scratch_STATUS, dst, mx->dom_rows)
+   {  return mclgUnionv2(mx, coldom, parm_restrict, scratch_STATUS, dst, mx->dom_rows)
 ;  }
 
 
 mclv* mclgUnionv2
 (  const mclx* mx
 ,  const mclv* coldom
-,  const mclv* restrict
+,  const mclv* parm_restrict
 ,  mcxenum scratch_STATUS
 ,  mclv* dst
 ,  mclv* scratch
@@ -1559,8 +1559,8 @@ mclv* mclgUnionv2
                )
                continue               /* SNH if coldom is subset of mx->dom_cols */
             ;  if
-               (  restrict
-               && 0 > (o_restrict = mclvGetIvpOffset(restrict, idx, o_restrict))
+               (  parm_restrict
+               && 0 > (o_restrict = mclvGetIvpOffset(parm_restrict, idx, o_restrict))
                )
                continue                /* not found in restriction domain */
 
diff --git a/src/impala/matrix.h b/src/impala/matrix.h
index f63d16d..7e0c498 100644
--- a/src/impala/matrix.h
+++ b/src/impala/matrix.h
@@ -734,7 +734,7 @@ enum
 mclv* mclgUnionv
 (  mclx* mx                   /*  mx->dom_rows used as scratch area     */
 ,  const mclv* dom_cols       /*  take union over these columns in mx   */
-,  const mclv* restrict       /*  only consider row entries in restrict */
+,  const mclv* parm_restrict       /*  only consider row entries in restrict */
 ,  mcxenum SCRATCH_STATUS     /*  if ready also returned ready          */
 ,  mclv* dst
 )  ;
@@ -755,7 +755,7 @@ mclv* mclgUnionv
 mclv* mclgUnionv2             /*  This one has a const matrix argument, additional scratch */
 (  const mclx* mx
 ,  const mclv* dom_cols
-,  const mclv* restrict
+,  const mclv* parm_restrict
 ,  mcxenum SCRATCH_STATUS
 ,  mclv* dst
 ,  mclv* scratch