diff --git a/app/main.F90 b/app/main.f90
similarity index 100%
rename from app/main.F90
rename to app/main.f90
diff --git a/fpm.toml b/fpm.toml
index e9a5070..318926b 100644
--- a/fpm.toml
+++ b/fpm.toml
@@ -4,11 +4,6 @@ license = "see LICENSE.txt"
 author = "Damian Rouson, David Torres,  Dominick Martinez, Jeremiah Bailey, and Brad Richardson"
 maintainer = "rouson@lbl.gov"
 
-[[executable]]
-name = "matcha"
-source-dir="app"
-main = "main.F90"
-
 [dependencies]
 assert = {git = "https://github.com/sourceryinstitute/assert", tag = "1.5.0"}
-sourcery = {git = "https://github.com/sourceryinstitute/sourcery", tag = "4.5.0"}
+sourcery = {git = "https://github.com/sourceryinstitute/sourcery", tag = "4.5.1"}
diff --git a/src/matcha/subdomain_m.f90 b/src/matcha/subdomain_m.f90
index 7e4326d..72c9cbf 100644
--- a/src/matcha/subdomain_m.f90
+++ b/src/matcha/subdomain_m.f90
@@ -10,18 +10,18 @@ module subdomain_m
   contains
     procedure, pass(self) :: define
     procedure, pass(self) :: step
-    procedure :: laplacian
-    generic :: operator(.laplacian.) => laplacian
     procedure, pass(rhs) :: multiply
+    generic :: operator(.laplacian.) => laplacian
     generic :: operator(*) => multiply
-    procedure :: add
     generic :: operator(+) => add
-    procedure :: assign_and_sync
     generic :: assignment(=) => assign_and_sync
     procedure dx
     procedure dy
     procedure dz
     procedure values
+    procedure, private :: laplacian
+    procedure, private :: add
+    procedure, private :: assign_and_sync
   end type
 
   interface