diff --git a/src/spicelib/analysis/cktsetup.c b/src/spicelib/analysis/cktsetup.c
index 6e22c3b0a..d858fca55 100644
--- a/src/spicelib/analysis/cktsetup.c
+++ b/src/spicelib/analysis/cktsetup.c
@@ -127,6 +127,7 @@ CKTsetup(CKTcircuit *ckt)
 
         /* Allocate space for the matrix diagonal data */
         if(num_nodes > 0) {
+            FREE(ckt->enh->rshunt_data.diag);
             ckt->enh->rshunt_data.diag =
                  TMALLOC(double *, num_nodes);
         }