diff --git a/src/stdio/getdelim.c b/src/stdio/getdelim.c
index d2f5b15a..df114441 100644
--- a/src/stdio/getdelim.c
+++ b/src/stdio/getdelim.c
@@ -55,9 +55,11 @@ ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restric
 			*s = tmp;
 			*n = m;
 		}
-		memcpy(*s+i, f->rpos, k);
-		f->rpos += k;
-		i += k;
+		if (k) {
+			memcpy(*s+i, f->rpos, k);
+			f->rpos += k;
+			i += k;
+		}
 		if (z) break;
 		if ((c = getc_unlocked(f)) == EOF) {
 			if (!i || !feof(f)) {