diff --git a/changelog/dmd.postfix-this-attributes.dd b/changelog/dmd.postfix-this-attributes.dd
new file mode 100644
index 0000000000..1a299d1aea
--- /dev/null
+++ b/changelog/dmd.postfix-this-attributes.dd
@@ -0,0 +1,13 @@
+Postfix type qualifier method attributes for `-H` and `-D`
+
+`.di` interface file generation and Ddoc output will now have type qualifier
+attributes placed after the parameter list for methods (and constructors).
+This avoids confusion with the return type.
+
+---
+struct S
+{
+    const int f(); // before
+    int f() const; // now
+}
+---
diff --git a/compiler/src/dmd/hdrgen.d b/compiler/src/dmd/hdrgen.d
index dfb90d6c6a..d4c99255fd 100644
--- a/compiler/src/dmd/hdrgen.d
+++ b/compiler/src/dmd/hdrgen.d
@@ -3927,7 +3927,7 @@ private void visitFuncIdentWithPrefix(TypeFunction t, const Identifier ident, Te
 
     /* Use 'storage class' (prefix) style for attributes
      */
-    if (t.mod && !hgs.ddoc)
+    if (t.mod && !(hgs.ddoc || hgs.hdrgen))
     {
         MODtoBuffer(buf, t.mod);
         buf.writeByte(' ');
@@ -3977,8 +3977,8 @@ private void visitFuncIdentWithPrefix(TypeFunction t, const Identifier ident, Te
         buf.writeByte(')');
     }
     parametersToBuffer(t.parameterList, buf, hgs);
-    // postfix TypeCtor attributes are more readable
-    if (t.mod && hgs.ddoc)
+    // postfix this attributes are more readable
+    if (t.mod && (hgs.ddoc || hgs.hdrgen))
     {
         buf.writeByte(' ');
         MODtoBuffer(buf, t.mod);
diff --git a/compiler/test/compilable/extra-files/header1.di b/compiler/test/compilable/extra-files/header1.di
index 91422fed8a..a894d0847b 100644
--- a/compiler/test/compilable/extra-files/header1.di
+++ b/compiler/test/compilable/extra-files/header1.di
@@ -359,8 +359,8 @@ int bar11(T)()
 }
 struct S6360
 {
-	const pure nothrow @property long weeks1();
-	const pure nothrow @property long weeks2();
+	pure nothrow @property long weeks1() const;
+	pure nothrow @property long weeks2() const;
 }
 struct S12
 {
@@ -369,10 +369,10 @@ struct S12
 }
 struct T12
 {
-	immutable this()(int args)
+	this()(int args) immutable
 	{
 	}
-	immutable this(A...)(A args)
+	this(A...)(A args) immutable
 	{
 	}
 }
@@ -502,7 +502,7 @@ size_t magic();
 class Foo2A
 {
 	immutable(FooA) Dummy = new immutable(FooA);
-	private immutable pure nothrow @nogc @safe this();
+	private pure nothrow @nogc @safe this() immutable;
 }
 struct Foo3A(T)
 {
@@ -560,4 +560,4 @@ interface I12344
 		assert(result > 0);
 	}
 	;
-}
+}
\ No newline at end of file
diff --git a/compiler/test/compilable/extra-files/header1i.di b/compiler/test/compilable/extra-files/header1i.di
index a77f3cb094..754c7ac80b 100644
--- a/compiler/test/compilable/extra-files/header1i.di
+++ b/compiler/test/compilable/extra-files/header1i.di
@@ -452,11 +452,11 @@ int bar11(T)()
 }
 struct S6360
 {
-	const pure nothrow @property long weeks1()
+	pure nothrow @property long weeks1() const
 	{
 		return 0;
 	}
-	const pure nothrow @property long weeks2()
+	pure nothrow @property long weeks2() const
 	{
 		return 0;
 	}
@@ -472,10 +472,10 @@ struct S12
 }
 struct T12
 {
-	immutable this()(int args)
+	this()(int args) immutable
 	{
 	}
-	immutable this(A...)(A args)
+	this(A...)(A args) immutable
 	{
 	}
 }
@@ -624,7 +624,7 @@ size_t magic()
 class Foo2A
 {
 	immutable(FooA) Dummy = new immutable(FooA);
-	private immutable pure nothrow @nogc @safe this()
+	private pure nothrow @nogc @safe this() immutable
 	{
 	}
 }
@@ -715,4 +715,4 @@ interface I12344
 		assert(result > 0);
 	}
 	;
-}
+}
\ No newline at end of file
diff --git a/compiler/test/compilable/header18365.d b/compiler/test/compilable/header18365.d
index 7e51fb26cc..8846c86c44 100644
--- a/compiler/test/compilable/header18365.d
+++ b/compiler/test/compilable/header18365.d
@@ -13,7 +13,7 @@ struct FullCaseEntry
 	ubyte n;
 	ubyte size;
 	ubyte entry_len;
-	auto const pure nothrow @nogc @property @trusted value() return
+	auto pure nothrow @nogc @property @trusted value() const return
 	{
 		return seq[0..entry_len];
 	}