diff --git a/src/json.hpp b/src/json.hpp
index 5ad77f9d..4891ddfb 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -6570,10 +6570,10 @@ class basic_json
         {
             case 8:
             {
-                vec.push_back(static_cast<uint8_t>((number >> 070) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 060) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 050) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 040) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 070) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 060) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 050) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 040) & 0xff));
                 // intentional fall-through
             }
 
diff --git a/src/json.hpp.re2c b/src/json.hpp.re2c
index 84c0e893..518889e0 100644
--- a/src/json.hpp.re2c
+++ b/src/json.hpp.re2c
@@ -6570,10 +6570,10 @@ class basic_json
         {
             case 8:
             {
-                vec.push_back(static_cast<uint8_t>((number >> 070) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 060) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 050) & 0xff));
-                vec.push_back(static_cast<uint8_t>((number >> 040) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 070) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 060) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 050) & 0xff));
+                vec.push_back(static_cast<uint8_t>((static_cast<uint64_t>(number) >> 040) & 0xff));
                 // intentional fall-through
             }