diff --git a/src/spicelib/devices/vsrc/vsrcacct.c b/src/spicelib/devices/vsrc/vsrcacct.c
index df890ed76..cd7d1111a 100644
--- a/src/spicelib/devices/vsrc/vsrcacct.c
+++ b/src/spicelib/devices/vsrc/vsrcacct.c
@@ -65,7 +65,7 @@ VSRCaccept(CKTcircuit *ckt, GENmodel *inModel)
                             && here->VSRCcoeffs[4] != 0.0
                             ? here->VSRCcoeffs[4] : ckt->CKTstep;
                         PW = here->VSRCfunctionOrder > 5
-                            && here->VSRCcoeffs[5] != 0.0
+                            && here->VSRCcoeffs[5] >= 0.0
                             ? here->VSRCcoeffs[5] : ckt->CKTfinalTime;
                         PER = here->VSRCfunctionOrder > 6
                             && here->VSRCcoeffs[6] != 0.0
diff --git a/src/spicelib/devices/vsrc/vsrcload.c b/src/spicelib/devices/vsrc/vsrcload.c
index c74c9a756..0ecf99c25 100644
--- a/src/spicelib/devices/vsrc/vsrcload.c
+++ b/src/spicelib/devices/vsrc/vsrcload.c
@@ -112,7 +112,7 @@ VSRCload(GENmodel *inModel, CKTcircuit *ckt)
                            && here->VSRCcoeffs[4] != 0.0
                            ? here->VSRCcoeffs[4] : ckt->CKTstep;
                         PW = here->VSRCfunctionOrder > 5
-                           && here->VSRCcoeffs[5] != 0.0
+                            && here->VSRCcoeffs[5] >= 0.0
                            ? here->VSRCcoeffs[5] : ckt->CKTfinalTime;
                         PER = here->VSRCfunctionOrder > 6
                            && here->VSRCcoeffs[6] != 0.0