diff --git a/core/stringstream.c b/core/stringstream.c
index c6052b0..6b00850 100644
--- a/core/stringstream.c
+++ b/core/stringstream.c
@@ -6,6 +6,8 @@
 
 void b_stringstream_begin(b_stringstream *ss, char *buf, size_t max)
 {
+	memset(ss, 0x0, sizeof *ss);
+
 	ss->ss_buf = buf;
 	ss->ss_max = max;
 	ss->ss_len = 0;
@@ -14,6 +16,8 @@ void b_stringstream_begin(b_stringstream *ss, char *buf, size_t max)
 
 void b_stringstream_begin_dynamic(b_stringstream *ss)
 {
+	memset(ss, 0x0, sizeof *ss);
+
 	ss->ss_buf = NULL;
 	ss->ss_max = 0;
 	ss->ss_len = 0;