diff --git a/src/cc65/error.c b/src/cc65/error.c
index 858a80826..c3ebebf77 100644
--- a/src/cc65/error.c
+++ b/src/cc65/error.c
@@ -67,7 +67,7 @@ IntStack WarningsAreErrors  = INTSTACK(0);  /* Treat warnings as errors */
 IntStack WarnConstComparison= INTSTACK(1);  /* - constant comparison results */
 IntStack WarnNoEffect       = INTSTACK(1);  /* - statements without an effect */
 IntStack WarnRemapZero      = INTSTACK(1);  /* - remapping character code zero */
-IntStack WarnStructParam    = INTSTACK(1);  /* - structs passed by val */
+IntStack WarnStructParam    = INTSTACK(0);  /* - structs passed by val */
 IntStack WarnUnknownPragma  = INTSTACK(1);  /* - unknown #pragmas */
 IntStack WarnUnusedLabel    = INTSTACK(1);  /* - unused labels */
 IntStack WarnUnusedParam    = INTSTACK(1);  /* - unused parameters */