diff --git a/src/strings.cpp b/src/strings.cpp
--- a/src/strings.cpp
+++ b/src/strings.cpp
@@ -715,6 +715,8 @@ static char *FormatString(char *buff, co
 			case SCC_NEWGRF_PRINT_WORD_STRING_ID: {
 				StringID substr = args->GetInt32(SCC_NEWGRF_PRINT_WORD_STRING_ID);
 				str_stack.push(GetStringPtr(substr));
+				casei = modifier >> 24;
+				modifier = 0;
 				break;
 			}