2 files changed, 2 insertions, 2 deletions
diff --git a/src/cmd/tbl/t5.c b/src/cmd/tbl/t5.c
index 8b7a65d8..3b12d98f 100644
--- a/src/cmd/tbl/t5.c
+++ b/src/cmd/tbl/t5.c
@@ -23,7 +23,7 @@ gettbl(void)
 			break;
 		}
 		fullbot[nlin] = 0;
-		if (cstore[0] == '.' && !isdigit(cstore[1])) {
+		if (cstore[0] == '.' && !isdigit((uchar)cstore[1])) {
 			instead[nlin] = cstore;
 			while (*cstore++)
 				;
diff --git a/src/cmd/tbl/t9.c b/src/cmd/tbl/t9.c
index 379126d2..69e9d6c7 100644
--- a/src/cmd/tbl/t9.c
+++ b/src/cmd/tbl/t9.c
@@ -29,7 +29,7 @@ domore(char *dataln)
 
 	if (prefix(".TE", dataln))
 		return(0);
-	if (dataln[0] == '.' && !isdigit(dataln[1])) {
+	if (dataln[0] == '.' && !isdigit((uchar)dataln[1])) {
 		Bprint(&tabout, "%s\n", dataln);
 		return(1);
 	}