diff --git a/lib/capn.c b/lib/capn.c
index c753e2c..60e139c 100644
--- a/lib/capn.c
+++ b/lib/capn.c
@@ -318,7 +318,7 @@ static char *struct_ptr(struct capn_segment *s, char *d, int minsz) {
 static capn_ptr read_ptr(struct capn_segment *s, char *d) {
 	capn_ptr ret = {CAPN_NULL};
 	uint64_t val;
-	char *e;
+	char *e = 0;
 
 	val = capn_flip64(*(uint64_t*) d);