diff --git a/src/common.cpp b/src/common.cpp
index 854fbd3a8..c7ced748c 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -338,6 +338,8 @@ static wcstring str2wcs_internal(const char *in, const size_t in_len) {
             // Determine whether to encode this character with our crazy scheme.
             if (wc >= ENCODE_DIRECT_BASE && wc < ENCODE_DIRECT_BASE + 256) {
                 use_encode_direct = true;
+            } else if ((wc >= 0xD800 && wc <= 0xDFFF) || static_cast<uint32_t>(wc) >= 0x110000) {
+                use_encode_direct = true;
             } else if (wc == INTERNAL_SEPARATOR) {
                 use_encode_direct = true;
             } else if (ret == static_cast<size_t>(-2)) {