diff --git a/src/newgrf_text.cpp b/src/newgrf_text.cpp
index 2a4f7f63fa..7d3f3224d3 100644
--- a/src/newgrf_text.cpp
+++ b/src/newgrf_text.cpp
@@ -324,7 +324,7 @@ struct UnmappedChoiceList : ZeroedMemoryAllocator {
 				char *str = this->strings[idx];
 
 				/* "<CASEn>" */
-				*d++ = i;
+				*d++ = i + 1;
 
 				/* "<LENn>" */
 				size_t len = strlen(str) + 1;