diff --git a/src/string/replace.c b/src/string/replace.c
index cb80d82..2ee84cd 100644
--- a/src/string/replace.c
+++ b/src/string/replace.c
@@ -24,6 +24,7 @@ size_t string_replace_cstring_cstring(str_t* x, const char* a, const char* d, si
     if (x->buffer == a) {
         x->buffer = realloc(x->buffer, dn + 1);
         memcpy(x->buffer, d, dn);
+        x->buffer[dn] = 0;
 
         return 1;
     }
@@ -68,6 +69,7 @@ size_t string_replace_cstring_char(str_t* x, const char* a, int dc, size_t maxn)
     if (x->buffer == a) {
         x->buffer = realloc(x->buffer, dn + 1);
         memcpy(x->buffer, d, dn);
+        x->buffer[dn] = 0;
 
         return 1;
     } else if (x->buffer < a && a < x->buffer + n) {