diff --git a/src/spicelib/devices/vsrc/vsrcpar.c b/src/spicelib/devices/vsrc/vsrcpar.c
index 0b235d279..703f73d73 100644
--- a/src/spicelib/devices/vsrc/vsrcpar.c
+++ b/src/spicelib/devices/vsrc/vsrcpar.c
@@ -42,6 +42,8 @@ VSRCparam(int param, IFvalue *value, GENinstance *inst, IFvalue *select)
 
     NG_IGNORE(select);
 
+    here->VSRCfuncTGiven = FALSE;
+
     switch (param) {
         case VSRC_DC:
             here->VSRCdcValue = value->rValue;