diff --git a/src/canmatrix/formats/dbc.py b/src/canmatrix/formats/dbc.py
index ffe3ffa9..6c4e3c5e 100644
--- a/src/canmatrix/formats/dbc.py
+++ b/src/canmatrix/formats/dbc.py
@@ -237,6 +237,9 @@ def dump(in_db, f, **options):
         for signal in frame.signals:
             if signal.cycle_time != 0:
                 signal.add_attribute("GenSigCycleTime", signal.cycle_time)
+            if signal.initial_value != 0 and "GenSigStartValue" not in db.signal_defines:
+                db.add_signal_defines("GenSigStartValue", 'FLOAT 0 100000000000')
+                
             if "GenSigStartValue" in db.signal_defines:
                 signal.add_attribute("GenSigStartValue", signal.phys2raw(None))