diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 6c911827778c7e36e4b34b59126cce40f4594dbe..281d281629b372a73425015c4c784dfd427d2fea 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -1833,6 +1833,8 @@ next_common_initial_sequence (tree &memb1, tree &memb2)
   if ((!lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (memb1)))
       != !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (memb2)))
     return false;
+  if (DECL_ALIGN (memb1) != DECL_ALIGN (memb2))
+    return false;
   if (!tree_int_cst_equal (bit_position (memb1), bit_position (memb2)))
     return false;
   return true;
@@ -1854,15 +1856,13 @@ layout_compatible_type_p (tree type1, tree type2)
   type2 = cp_build_qualified_type (type2, TYPE_UNQUALIFIED);
 
   if (TREE_CODE (type1) == ENUMERAL_TYPE)
-    return (TYPE_ALIGN (type1) == TYPE_ALIGN (type2)
-	    && tree_int_cst_equal (TYPE_SIZE (type1), TYPE_SIZE (type2))
+    return (tree_int_cst_equal (TYPE_SIZE (type1), TYPE_SIZE (type2))
 	    && same_type_p (finish_underlying_type (type1),
 			    finish_underlying_type (type2)));
 
   if (CLASS_TYPE_P (type1)
       && std_layout_type_p (type1)
       && std_layout_type_p (type2)
-      && TYPE_ALIGN (type1) == TYPE_ALIGN (type2)
       && tree_int_cst_equal (TYPE_SIZE (type1), TYPE_SIZE (type2)))
     {
       tree field1 = TYPE_FIELDS (type1);
diff --git a/gcc/testsuite/g++.dg/DRs/dr2583.C b/gcc/testsuite/g++.dg/DRs/dr2583.C
new file mode 100644
index 0000000000000000000000000000000000000000..e80834c621590be7803896d62502b01dc1f843d5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/DRs/dr2583.C
@@ -0,0 +1,45 @@
+// DR 2583 - Common initial sequence should consider over-alignment.
+// { dg-do compile { target c++11 } }
+
+#include <type_traits>
+
+struct A {
+  int i;
+  char c;
+};
+
+struct B {
+  int i;
+  alignas(8) char c;
+};
+
+struct C {
+  int i;
+  alignas(alignof(char)) char c;
+};
+
+struct D {
+  alignas(alignof(int)) int i;
+  char c;
+};
+
+struct S0 {
+  alignas(16) char x[128];
+  int i;
+};
+
+struct alignas(16) S1 {
+  char x[128];
+  int i;
+};
+
+#if __cpp_lib_is_layout_compatible >= 201907L
+static_assert (std::is_corresponding_member (&A::i, &B::i), "");
+static_assert (std::is_corresponding_member (&A::c, &B::c) == (alignof (char) == 8), "");
+static_assert (std::is_corresponding_member (&A::i, &C::i), "");
+static_assert (std::is_corresponding_member (&A::c, &C::c), "");
+static_assert (std::is_corresponding_member (&A::i, &D::i), "");
+static_assert (std::is_corresponding_member (&A::c, &D::c), "");
+static_assert (std::is_corresponding_member (&S0::x, &S1::x) == (alignof (char) == 16), "");
+static_assert (std::is_corresponding_member (&S0::i, &S1::i) == (alignof (char) == 16), "");
+#endif
diff --git a/gcc/testsuite/g++.dg/cpp2a/is-layout-compatible3.C b/gcc/testsuite/g++.dg/cpp2a/is-layout-compatible3.C
index c54858746606cf61671d204779637d4a43e34f22..8f48ba8679a11d868a538909eaa84c07bb3090ec 100644
--- a/gcc/testsuite/g++.dg/cpp2a/is-layout-compatible3.C
+++ b/gcc/testsuite/g++.dg/cpp2a/is-layout-compatible3.C
@@ -55,10 +55,10 @@ static_assert (!std::is_layout_compatible_v<K, L>);
 static_assert (!std::is_layout_compatible_v<M, N>);
 static_assert (!std::is_layout_compatible_v<O, P>);
 static_assert (!std::is_layout_compatible_v<P, D>);
-static_assert (!std::is_layout_compatible_v<Q, R>);
+static_assert (std::is_layout_compatible_v<Q, R>);
 static_assert (!std::is_layout_compatible_v<U, V>);
 static_assert (!std::is_layout_compatible_v<A, I>);
 static_assert (!std::is_layout_compatible_v<C, I>);
-static_assert (std::is_layout_compatible_v<E, F>);
+static_assert (!std::is_layout_compatible_v<E, F>);
 static_assert (std::is_layout_compatible_v<G, H>);
 static_assert (std::is_layout_compatible_v<C1, D1>);