diff --git a/lib/ash/resource/relationships/many_to_many.ex b/lib/ash/resource/relationships/many_to_many.ex
index c14c5d11..70fc587f 100644
--- a/lib/ash/resource/relationships/many_to_many.ex
+++ b/lib/ash/resource/relationships/many_to_many.ex
@@ -37,6 +37,7 @@ defmodule Ash.Resource.Relationships.ManyToMany do
     ],
     destination_field_on_join_table: [
       type: :atom,
+      required: true,
       doc:
         "The field on the join table that should line up with `destination_field` on the related resource. Default: [relationshihp_name]_id"
     ],
@@ -90,8 +91,7 @@ defmodule Ash.Resource.Relationships.ManyToMany do
            source_field: opts[:source_field],
            destination_field: opts[:destination_field],
            source_field_on_join_table: opts[:source_field_on_join_table],
-           destination_field_on_join_table:
-             opts[:destination_field_on_join_table] || :"#{name}_id"
+           destination_field_on_join_table: opts[:destination_field_on_join_table]
          }}
 
       {:error, errors} ->
diff --git a/test/actions/create_test.exs b/test/actions/create_test.exs
index 56c5227c..7e5bbac5 100644
--- a/test/actions/create_test.exs
+++ b/test/actions/create_test.exs
@@ -40,9 +40,11 @@ defmodule Ash.Test.Actions.CreateTest do
     end
 
     relationships do
-      has_one :profile, Profile
+      has_one :profile, Profile, destination_field: :author_id
 
-      has_many :posts, Ash.Test.Actions.CreateTest.Post, reverse_relationship: :author
+      has_many :posts, Ash.Test.Actions.CreateTest.Post,
+        reverse_relationship: :author,
+        destination_field: :author
     end
   end
 
diff --git a/test/actions/destroy_test.exs b/test/actions/destroy_test.exs
index 42274cbe..78a67d08 100644
--- a/test/actions/destroy_test.exs
+++ b/test/actions/destroy_test.exs
@@ -42,9 +42,9 @@ defmodule Ash.Test.Actions.DestroyTest do
     end
 
     relationships do
-      has_one :profile, Profile
+      has_one :profile, Profile, destination_field: :author_id
 
-      has_many :posts, Ash.Test.Actions.CreateTest.Post
+      has_many :posts, Ash.Test.Actions.CreateTest.Post, destination_field: :author_id
     end
   end
 
diff --git a/test/actions/read_test.exs b/test/actions/read_test.exs
index 95e6861f..e9864662 100644
--- a/test/actions/read_test.exs
+++ b/test/actions/read_test.exs
@@ -18,7 +18,7 @@ defmodule Ash.Test.Actions.ReadTest do
     end
 
     relationships do
-      has_many :posts, Ash.Test.Actions.ReadTest.Post
+      has_many :posts, Ash.Test.Actions.ReadTest.Post, destination_field: :author
     end
   end
 
diff --git a/test/actions/side_load_test.exs b/test/actions/side_load_test.exs
index 2d13d2f8..119c79d4 100644
--- a/test/actions/side_load_test.exs
+++ b/test/actions/side_load_test.exs
@@ -18,7 +18,9 @@ defmodule Ash.Test.Actions.SideLoadTest do
     end
 
     relationships do
-      has_many :posts, Ash.Test.Actions.SideLoadTest.Post, reverse_relationship: :author
+      has_many :posts, Ash.Test.Actions.SideLoadTest.Post,
+        reverse_relationship: :author,
+        destination_field: :author_id
     end
   end
 
diff --git a/test/actions/update_test.exs b/test/actions/update_test.exs
index 222ce9ba..fd88d424 100644
--- a/test/actions/update_test.exs
+++ b/test/actions/update_test.exs
@@ -40,9 +40,11 @@ defmodule Ash.Test.Actions.UpdateTest do
     end
 
     relationships do
-      has_one :profile, Profile
+      has_one :profile, Profile, destination_field: :author_id
 
-      has_many :posts, Ash.Test.Actions.UpdateTest.Post, reverse_relationship: :author
+      has_many :posts, Ash.Test.Actions.UpdateTest.Post,
+        reverse_relationship: :author,
+        destination_field: :author_id
     end
   end
 
diff --git a/test/filter/filter_test.exs b/test/filter/filter_test.exs
index 7f3d6a83..a68f0639 100644
--- a/test/filter/filter_test.exs
+++ b/test/filter/filter_test.exs
@@ -49,7 +49,7 @@ defmodule Ash.Test.Filter.FilterTest do
         reverse_relationship: :author2,
         destination_field: :author1_id
 
-      has_one :profile, Profile
+      has_one :profile, Profile, destination_field: :user_id
     end
   end
 
diff --git a/test/resource/relationships/has_many_test.exs b/test/resource/relationships/has_many_test.exs
index 9ab60ac8..4e1c6cb8 100644
--- a/test/resource/relationships/has_many_test.exs
+++ b/test/resource/relationships/has_many_test.exs
@@ -21,7 +21,7 @@ defmodule Ash.Test.Resource.Relationshihps.HasManyTest do
     test "it creates a relationship" do
       defposts do
         relationships do
-          has_many :foobar, FooBar
+          has_many :foobar, FooBar, destination_field: :post_id
         end
       end
 
@@ -60,7 +60,7 @@ defmodule Ash.Test.Resource.Relationshihps.HasManyTest do
         fn ->
           defposts do
             relationships do
-              has_many :foobar, FooBar, source_field: "foo"
+              has_many :foobar, FooBar, source_field: "foo", destination_field: :post_id
             end
           end
         end
diff --git a/test/resource/relationships/has_one_test.exs b/test/resource/relationships/has_one_test.exs
index 3684b3be..2e0d692b 100644
--- a/test/resource/relationships/has_one_test.exs
+++ b/test/resource/relationships/has_one_test.exs
@@ -21,7 +21,7 @@ defmodule Ash.Test.Resource.Relationshihps.HasOneTest do
     test "it creates a relationship" do
       defposts do
         relationships do
-          has_one :foobar, FooBar
+          has_one :foobar, FooBar, destination_field: :post_id
         end
       end
 
@@ -60,7 +60,7 @@ defmodule Ash.Test.Resource.Relationshihps.HasOneTest do
         fn ->
           defposts do
             relationships do
-              has_one :foobar, FooBar, source_field: "foo"
+              has_one :foobar, FooBar, source_field: "foo", destination_field: :post_id
             end
           end
         end
diff --git a/test/resource/relationships/many_to_many_test.exs b/test/resource/relationships/many_to_many_test.exs
index 78fbeb91..7c026a04 100644
--- a/test/resource/relationships/many_to_many_test.exs
+++ b/test/resource/relationships/many_to_many_test.exs
@@ -21,7 +21,10 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
     test "it creates a relationship and a join relationship" do
       defposts do
         relationships do
-          many_to_many :related_posts, Post, through: SomeResource
+          many_to_many :related_posts, Post,
+            through: SomeResource,
+            source_field_on_join_table: :post_id,
+            destination_field_on_join_table: :related_post_id
         end
       end
 
@@ -29,7 +32,7 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
                %Ash.Resource.Relationships.HasMany{
                  cardinality: :many,
                  destination: SomeResource,
-                 destination_field: :posts_id,
+                 destination_field: :post_id,
                  name: :related_posts_join_assoc,
                  source: Ash.Test.Resource.Relationships.ManyToManyTest.Post,
                  source_field: :id,
@@ -40,11 +43,11 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
                  cardinality: :many,
                  destination: Ash.Test.Resource.Relationships.ManyToManyTest.Post,
                  destination_field: :id,
-                 destination_field_on_join_table: :related_posts_id,
+                 destination_field_on_join_table: :related_post_id,
                  name: :related_posts,
                  source: Ash.Test.Resource.Relationships.ManyToManyTest.Post,
                  source_field: :id,
-                 source_field_on_join_table: :posts_id,
+                 source_field_on_join_table: :post_id,
                  through: SomeResource,
                  type: :many_to_many,
                  reverse_relationship: nil
@@ -61,7 +64,10 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
         fn ->
           defposts do
             relationships do
-              many_to_many :foobars, Foobar, through: "some_table"
+              many_to_many :foobars, Foobar,
+                through: "some_table",
+                source_field_on_join_table: :source_post_id,
+                destination_field_on_join_table: :destination_post_id
             end
           end
         end
@@ -71,7 +77,10 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
     test "you can pass a module to `through`" do
       defposts do
         relationships do
-          many_to_many :foobars, Foobar, through: FooBars
+          many_to_many :foobars, Foobar,
+            through: FooBars,
+            source_field_on_join_table: :source_post_id,
+            destination_field_on_join_table: :destination_post_id
         end
       end
     end
@@ -83,7 +92,10 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
         fn ->
           defposts do
             relationships do
-              many_to_many :foobars, Foobar, through: FooBars, source_field_on_join_table: "what"
+              many_to_many :foobars, Foobar,
+                through: FooBars,
+                source_field_on_join_table: "what",
+                destination_field_on_join_table: :destination_post_id
             end
           end
         end
@@ -99,7 +111,8 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
             relationships do
               many_to_many :foobars, Foobar,
                 through: FooBar,
-                destination_field_on_join_table: "what"
+                destination_field_on_join_table: "what",
+                source_field_on_join_table: :source_post_id
             end
           end
         end
@@ -115,7 +128,9 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
             relationships do
               many_to_many :foobars, Foobar,
                 through: FooBar,
-                source_field: "what"
+                source_field: "what",
+                source_field_on_join_table: :source_post_id,
+                destination_field_on_join_table: :destination_post_id
             end
           end
         end
@@ -131,7 +146,9 @@ defmodule Ash.Test.Resource.Relationships.ManyToManyTest do
             relationships do
               many_to_many :foobars, Foobar,
                 through: FooBars,
-                destination_field: "what"
+                destination_field: "what",
+                source_field_on_join_table: :source_post_id,
+                destination_field_on_join_table: :destination_post_id
             end
           end
         end