diff --git a/internal/provider/collect.go b/internal/provider/collect.go
index 93bf3963e..6658c8067 100644
--- a/internal/provider/collect.go
+++ b/internal/provider/collect.go
@@ -161,12 +161,15 @@ func merge(sources *fileSources, registerd map[int64]*goMigration) ([]*migration
 	// wholesale as part of migrations. This allows users to build a custom binary that only embeds
 	// the SQL migration files.
 	for version, r := range registerd {
-		fullpath := "manually registered (no source)"
+		var fullpath string
 		if s := sources.lookup(TypeGo, version); s != nil {
 			fullpath = s.Fullpath
 		}
 		// Ensure there are no duplicate versions.
 		if existing, ok := migrationLookup[version]; ok {
+			if fullpath == "" {
+				fullpath = "manually registered (no source)"
+			}
 			return nil, fmt.Errorf("found duplicate migration version %d:\n\texisting:%v\n\tcurrent:%v",
 				version,
 				existing.Source.Fullpath,
@@ -174,6 +177,7 @@ func merge(sources *fileSources, registerd map[int64]*goMigration) ([]*migration
 			)
 		}
 		m := &migration{
+			// Note, the fullpath may be empty if the migration was registered manually.
 			Source: newSource(TypeGo, fullpath, version),
 			Go:     r,
 		}
diff --git a/internal/provider/collect_test.go b/internal/provider/collect_test.go
index 08834db85..401a1ce40 100644
--- a/internal/provider/collect_test.go
+++ b/internal/provider/collect_test.go
@@ -254,9 +254,34 @@ func TestMerge(t *testing.T) {
 			check.Number(t, len(migrations), 5)
 			assertMigration(t, migrations[0], newSource(TypeSQL, "00001_foo.sql", 1))
 			assertMigration(t, migrations[1], newSource(TypeSQL, "00002_bar.sql", 2))
-			assertMigration(t, migrations[2], newSource(TypeGo, "manually registered (no source)", 3))
+			assertMigration(t, migrations[2], newSource(TypeGo, "", 3))
 			assertMigration(t, migrations[3], newSource(TypeSQL, "00005_baz.sql", 5))
-			assertMigration(t, migrations[4], newSource(TypeGo, "manually registered (no source)", 6))
+			assertMigration(t, migrations[4], newSource(TypeGo, "", 6))
+		})
+	})
+	t.Run("partial_go_files_on_disk", func(t *testing.T) {
+		mapFS := fstest.MapFS{
+			"migrations/00001_foo.sql": sqlMapFile,
+			"migrations/00002_bar.go":  &fstest.MapFile{Data: []byte(`package migrations`)},
+		}
+		fsys, err := fs.Sub(mapFS, "migrations")
+		check.NoError(t, err)
+		sources, err := collectFileSources(fsys, false, nil)
+		check.NoError(t, err)
+		t.Run("unregistered_all", func(t *testing.T) {
+			migrations, err := merge(sources, map[int64]*goMigration{
+				// This is the only Go file on disk.
+				2: {version: 2},
+				// These are not on disk. Explicitly registered.
+				3: {version: 3},
+				6: {version: 6},
+			})
+			check.NoError(t, err)
+			check.Number(t, len(migrations), 4)
+			assertMigration(t, migrations[0], newSource(TypeSQL, "00001_foo.sql", 1))
+			assertMigration(t, migrations[1], newSource(TypeGo, "00002_bar.go", 2))
+			assertMigration(t, migrations[2], newSource(TypeGo, "", 3))
+			assertMigration(t, migrations[3], newSource(TypeGo, "", 6))
 		})
 	})
 }