diff --git a/changes/bug20048 b/changes/bug20048
new file mode 100644
index 0000000000..0874e97e7a
--- /dev/null
+++ b/changes/bug20048
@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - Implement smartlist_add_strdup() function. Replaces the use of
+      smartlist_add(sl, tor_strdup(str)). Fixes bug 20048. 
+
diff --git a/src/common/util.c b/src/common/util.c
index 9162967907..02ccf4ff0f 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -3532,6 +3532,17 @@ smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
   smartlist_add(sl, str);
 }
 
+/** Append a copy of string to sl */
+void
+smartlist_add_strdup(struct smartlist_t *sl, const char *string)
+{
+  char *copy;
+
+  copy = tor_strdup(string);
+
+  smartlist_add(sl, copy);
+}
+
 /** Return a new list containing the filenames in the directory <b>dirname</b>.
  * Return NULL on error or if <b>dirname</b> is not a directory.
  */
diff --git a/src/common/util.h b/src/common/util.h
index 479fc8d610..37f4bed1cb 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -239,6 +239,7 @@ void smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
 void smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
                              va_list args)
   CHECK_PRINTF(2, 0);
+void smartlist_add_strdup(struct smartlist_t *sl, const char *string);
 
 /* Time helpers */
 long tv_udiff(const struct timeval *start, const struct timeval *end);