diff --git a/src/codegen.cpp b/src/codegen.cpp
index 71caf18e2..2548b3fa8 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -3218,7 +3218,8 @@ static LLVMValueRef ir_render_decl_var(CodeGen *g, IrExecutable *executable,
         assert(var->value->type == init_value->value.type);
         ZigType *var_ptr_type = get_pointer_to_type_extra(g, var->value->type, false, false,
                 PtrLenSingle, var->align_bytes, 0, 0);
-        gen_assign_raw(g, var->value_ref, var_ptr_type, ir_llvm_value(g, init_value));
+        LLVMValueRef llvm_init_val = ir_llvm_value(g, init_value);
+        gen_assign_raw(g, var->value_ref, var_ptr_type, llvm_init_val);
     } else {
         bool want_safe = ir_want_runtime_safety(g, &decl_var_instruction->base);
         if (want_safe) {
@@ -5863,12 +5864,20 @@ static LLVMValueRef gen_const_val(CodeGen *g, ConstExprValue *const_val, const c
                 LLVMValueRef tag_value = bigint_to_llvm_const(type_entry->data.unionation.tag_type->type_ref,
                         &const_val->data.x_union.tag);
 
-                LLVMValueRef fields[2];
+                LLVMValueRef fields[3];
                 fields[type_entry->data.unionation.gen_union_index] = union_value_ref;
                 fields[type_entry->data.unionation.gen_tag_index] = tag_value;
 
                 if (make_unnamed_struct) {
-                    return LLVMConstStruct(fields, 2, false);
+                    LLVMValueRef result = LLVMConstStruct(fields, 2, false);
+                    size_t expected_sz = LLVMStoreSizeOfType(g->target_data_ref, type_entry->type_ref);
+                    size_t actual_sz = LLVMStoreSizeOfType(g->target_data_ref, LLVMTypeOf(result));
+                    if (actual_sz < expected_sz) {
+                        unsigned pad_sz = expected_sz - actual_sz;
+                        fields[2] = LLVMGetUndef(LLVMArrayType(LLVMInt8Type(), pad_sz));
+                        result = LLVMConstStruct(fields, 3, false);
+                    }
+                    return result;
                 } else {
                     return LLVMConstNamedStruct(type_entry->type_ref, fields, 2);
                 }
diff --git a/test/behavior.zig b/test/behavior.zig
index 25997a2a4..cae8c4b0f 100644
--- a/test/behavior.zig
+++ b/test/behavior.zig
@@ -10,6 +10,7 @@ comptime {
     _ = @import("cases/bool.zig");
     _ = @import("cases/bugs/1111.zig");
     _ = @import("cases/bugs/1277.zig");
+    _ = @import("cases/bugs/1381.zig");
     _ = @import("cases/bugs/1421.zig");
     _ = @import("cases/bugs/394.zig");
     _ = @import("cases/bugs/655.zig");
diff --git a/test/cases/bugs/1381.zig b/test/cases/bugs/1381.zig
new file mode 100644
index 000000000..2d452da15
--- /dev/null
+++ b/test/cases/bugs/1381.zig
@@ -0,0 +1,21 @@
+const std = @import("std");
+
+const B = union(enum) {
+    D: u8,
+    E: u16,
+};
+
+const A = union(enum) {
+    B: B,
+    C: u8,
+};
+
+test "union that needs padding bytes inside an array" {
+    var as = []A{
+        A{ .B = B{ .D = 1 } },
+        A{ .B = B{ .D = 1 } },
+    };
+
+    const a = as[0].B;
+    std.debug.assertOrPanic(a.D == 1);
+}