diff --git a/src/c/dpp.c b/src/c/dpp.c
index 1fcb9f0bb..50b79d435 100644
--- a/src/c/dpp.c
+++ b/src/c/dpp.c
@@ -217,7 +217,7 @@ read_name(int is_symbol)
 	do {
 		if (isalpha(c))
 			; /* c=tolower(c) */
-		else if (isnumber(c))
+		else if (isdigit(c))
 			;
 		else if (c == '-' || c == '_')
 			c = '_';