diff --git a/src/stage1/codegen.cpp b/src/stage1/codegen.cpp
index d0bb9b4411..6a02f2912b 100644
--- a/src/stage1/codegen.cpp
+++ b/src/stage1/codegen.cpp
@@ -7038,7 +7038,14 @@ static LLVMValueRef gen_const_ptr_struct_recursive(CodeGen *g, ZigValue *struct_
         LLVMConstNull(get_llvm_type(g, u32)),
         LLVMConstInt(get_llvm_type(g, u32), field_index, false),
     };
-    return LLVMConstInBoundsGEP(base_ptr, indices, 2);
+
+    // The structure pointed by base_ptr may include trailing padding for
+    // alignment purposes and have the following LLVM type: <{ %T, [N x i8] }>.
+    // Add an extra bitcast as we're only interested in the %T part.
+    assert(handle_is_ptr(g, struct_const_val->type));
+    LLVMValueRef casted_base_ptr = LLVMConstBitCast(base_ptr,
+            LLVMPointerType(get_llvm_type(g, struct_const_val->type), 0));
+    return LLVMConstInBoundsGEP(casted_base_ptr, indices, 2);
 }
 
 static LLVMValueRef gen_const_ptr_err_union_code_recursive(CodeGen *g, ZigValue *err_union_const_val) {
diff --git a/test/stage1/behavior.zig b/test/stage1/behavior.zig
index 86e9619d26..662a7383b3 100644
--- a/test/stage1/behavior.zig
+++ b/test/stage1/behavior.zig
@@ -50,6 +50,7 @@ comptime {
     _ = @import("behavior/bugs/4769_b.zig");
     _ = @import("behavior/bugs/4769_c.zig");
     _ = @import("behavior/bugs/4954.zig");
+    _ = @import("behavior/bugs/5398.zig");
     _ = @import("behavior/bugs/5413.zig");
     _ = @import("behavior/bugs/5474.zig");
     _ = @import("behavior/bugs/5487.zig");
diff --git a/test/stage1/behavior/bugs/5398.zig b/test/stage1/behavior/bugs/5398.zig
new file mode 100644
index 0000000000..fdfd0b3698
--- /dev/null
+++ b/test/stage1/behavior/bugs/5398.zig
@@ -0,0 +1,31 @@
+const std = @import("std");
+const testing = std.testing;
+
+pub const Mesh = struct {
+    id: u32,
+};
+pub const Material = struct {
+    transparent: bool = true,
+    emits_shadows: bool = true,
+    render_color: bool = true,
+};
+pub const Renderable = struct {
+    material: Material,
+    // The compiler inserts some padding here to ensure Mesh is correctly aligned.
+    mesh: Mesh,
+};
+
+var renderable: Renderable = undefined;
+
+test "assignment of field with padding" {
+    renderable = Renderable{
+        .mesh = Mesh{ .id = 0 },
+        .material = Material{
+            .transparent = false,
+            .emits_shadows = false,
+        },
+    };
+    testing.expectEqual(false, renderable.material.transparent);
+    testing.expectEqual(false, renderable.material.emits_shadows);
+    testing.expectEqual(true, renderable.material.render_color);
+}