1 files changed, 4 insertions, 3 deletions

diff --git a/ws.c b/ws.c
index 46a77bcad6..903bfcd53e 100644
--- a/ws.c
+++ b/ws.c
@@ -29,6 +29,7 @@ unsigned parse_whitespace_rule(const char *string)
 		int i;
 		size_t len;
 		const char *ep;
+		const char *arg;
 		int negated = 0;
 
 		string = string + strspn(string, ", \t\n\r");
@@ -52,15 +53,15 @@ unsigned parse_whitespace_rule(const char *string)
 				rule |= whitespace_rule_names[i].rule_bits;
 			break;
 		}
-		if (strncmp(string, "tabwidth=", 9) == 0) {
-			unsigned tabwidth = atoi(string + 9);
+		if (skip_prefix(string, "tabwidth=", &arg)) {
+			unsigned tabwidth = atoi(arg);
 			if (0 < tabwidth && tabwidth < 0100) {
 				rule &= ~WS_TAB_WIDTH_MASK;
 				rule |= tabwidth;
 			}
 			else
 				warning("tabwidth %.*s out of range",
-					(int)(len - 9), string + 9);
+					(int)(ep - arg), arg);
 		}
 		string = ep;
 	}