diff --git a/include/aws/common/string.h b/include/aws/common/string.h
index 37ec2f99e..1b969552e 100644
--- a/include/aws/common/string.h
+++ b/include/aws/common/string.h
@@ -325,6 +325,7 @@ bool aws_byte_buf_write_from_whole_string(
 
 /**
  * Creates an aws_byte_cursor from an existing string.
+ * If the src is NULL, it returns an empty cursor
  */
 AWS_COMMON_API
 struct aws_byte_cursor aws_byte_cursor_from_string(const struct aws_string *src);
diff --git a/source/string.c b/source/string.c
index 2fd791230..e68f6b284 100644
--- a/source/string.c
+++ b/source/string.c
@@ -416,7 +416,12 @@ bool aws_byte_buf_write_from_whole_string(
  * Creates an aws_byte_cursor from an existing string.
  */
 struct aws_byte_cursor aws_byte_cursor_from_string(const struct aws_string *src) {
-    AWS_PRECONDITION(aws_string_is_valid(src));
+    if (!src) {
+        struct aws_byte_cursor cursor;
+        AWS_ZERO_STRUCT(cursor);
+        return cursor;
+    }
+
     return aws_byte_cursor_from_array(aws_string_bytes(src), src->len);
 }