diff --git a/lld/ELF/Symbols.h b/lld/ELF/Symbols.h
--- a/lld/ELF/Symbols.h
+++ b/lld/ELF/Symbols.h
@@ -78,11 +78,11 @@
   //  - An undefined weak is still weak when it resolves to a shared library.
   //  - An undefined weak will not extract archive members, but we have to
   //    remember it is weak.
-  uint8_t binding;
+  uint8_t binding : 4;
 
   // The following fields have the same meaning as the ELF symbol attributes.
-  uint8_t type;    // symbol type
-  uint8_t stOther; // st_other field value
+  uint8_t type : 4; // symbol type
+  uint8_t stOther;  // st_other field value
 
   uint8_t symbolKind;