diff --git a/xlhtml/xlhtml.c b/xlhtml/xlhtml.c
index c3424dc..95fb5fe 100644
--- a/xlhtml/xlhtml.c
+++ b/xlhtml/xlhtml.c
@@ -770,6 +770,9 @@ void main_line_processor(U16 opcode, U16 version, U32 count, U16 last, U8 data)
 
 	switch (opcode)
 	{
+		case 0x02:	/* File is password protected */
+			printf("File is password protected. Exiting...");
+			exit(1);
 		case 0x09:	/* BOF */
 			working_buffer[bufidx++] = data;
 			if (bufidx == last)