diff --git a/base/codevalidation.jl b/base/codevalidation.jl
index 7605a1654af16..10507aea2f386 100644
--- a/base/codevalidation.jl
+++ b/base/codevalidation.jl
@@ -27,8 +27,6 @@ const VALID_EXPR_HEADS = ObjectIdDict(
     :simdloop => 0:0
 )
 
-const ASSIGNED_FLAG = 0x02
-
 # @enum isn't defined yet, otherwise I'd use it for this
 const INVALID_EXPR_HEAD = "invalid expression head"
 const INVALID_EXPR_NARGS = "invalid number of expression args"
@@ -41,7 +39,6 @@ const SLOTTYPES_MISMATCH = "length(slotnames) != length(slottypes)"
 const SLOTTYPES_MISMATCH_UNINFERRED = "uninferred CodeInfo slottypes field is not `nothing`"
 const SSAVALUETYPES_MISMATCH = "not all SSAValues in AST have a type in ssavaluetypes"
 const SSAVALUETYPES_MISMATCH_UNINFERRED = "uninferred CodeInfo ssavaluetypes field does not equal the number of present SSAValues"
-const INVALID_ASSIGNMENT_SLOTFLAG = "slot has wrong assignment slotflag setting (bit flag 2 not set)"
 const NON_TOP_LEVEL_METHOD = "encountered `Expr` head `:method` in non-top-level code (i.e. `nargs` > 0)"
 const SIGNATURE_NARGS_MISMATCH = "method signature does not match number of method arguments"
 const SLOTNAMES_NARGS_MISMATCH = "CodeInfo for method contains fewer slotnames than the number of method arguments"
@@ -76,9 +73,6 @@ function validate_code!(errors::Vector{>:InvalidCodeError}, c::CodeInfo, is_top_
                     push!(errors, InvalidCodeError(INVALID_LVALUE, lhs))
                 elseif isa(lhs, SlotNumber) && !in(lhs.id, lhs_slotnums)
                     n = lhs.id
-                    if isassigned(c.slotflags, n) && !is_flag_set(c.slotflags[n], ASSIGNED_FLAG)
-                        push!(errors, InvalidCodeError(INVALID_ASSIGNMENT_SLOTFLAG, lhs))
-                    end
                     push!(lhs_slotnums, n)
                 end
                 if !is_valid_rvalue(rhs)
diff --git a/base/inference.jl b/base/inference.jl
index 2c899590a290a..78aaf2adbd8f1 100644
--- a/base/inference.jl
+++ b/base/inference.jl
@@ -53,7 +53,6 @@ end
 #     cond && use(a)
 
 # slot property bit flags
-const Slot_Assigned     = 2
 const Slot_AssignedOnce = 16
 const Slot_UsedUndef    = 32
 
@@ -5110,7 +5109,7 @@ function add_slot!(src::CodeInfo, @nospecialize(typ), is_sa::Bool, name::Symbol=
     id = length(src.slotnames) + 1
     push!(src.slotnames, name)
     push!(src.slottypes, typ)
-    push!(src.slotflags, Slot_Assigned + is_sa * Slot_AssignedOnce)
+    push!(src.slotflags, is_sa * Slot_AssignedOnce)
     return SlotNumber(id)
 end
 
diff --git a/src/method.c b/src/method.c
index 6f43a7b95d499..d32a6c19d881e 100644
--- a/src/method.c
+++ b/src/method.c
@@ -170,6 +170,8 @@ static void jl_code_info_set_ast(jl_code_info_t *li, jl_expr_t *ast)
     jl_gc_wb(li, li->slotflags);
     li->ssavaluetypes = jl_box_long(nssavalue);
     jl_gc_wb(li, li->ssavaluetypes);
+    // Flags that need to be copied to slotflags
+    const uint8_t vinfo_mask = 16 | 32 | 64;
     int i;
     for (i = 0; i < nslots; i++) {
         jl_value_t *vi = jl_array_ptr_ref(vis, i);
@@ -187,7 +189,7 @@ static void jl_code_info_set_ast(jl_code_info_t *li, jl_expr_t *ast)
             }
         }
         jl_array_ptr_set(li->slotnames, i, name);
-        jl_array_uint8_set(li->slotflags, i, jl_unbox_long(jl_array_ptr_ref(vi, 2)));
+        jl_array_uint8_set(li->slotflags, i, vinfo_mask & jl_unbox_long(jl_array_ptr_ref(vi, 2)));
     }
 }
 
diff --git a/test/codevalidation.jl b/test/codevalidation.jl
index 0ed65869dcad5..829df9759c473 100644
--- a/test/codevalidation.jl
+++ b/test/codevalidation.jl
@@ -105,13 +105,6 @@ errors = Core.Inference.validate_code(c)
 @test length(errors) == 1
 @test errors[1].kind === Core.Inference.SSAVALUETYPES_MISMATCH_UNINFERRED
 
-# INVALID_ASSIGNMENT_SLOTFLAG
-c = Core.Inference.copy_code_info(c0)
-c.slotflags[8] = 0x00
-errors = Core.Inference.validate_code(c)
-@test length(errors) == 1
-@test errors[1].kind === Core.Inference.INVALID_ASSIGNMENT_SLOTFLAG
-
 # SIGNATURE_NARGS_MISMATCH
 old_sig = mi.def.sig
 mi.def.sig = Tuple{1,2}