diff --git a/src/graycore.f90 b/src/gray_core.f90
similarity index 99%
rename from src/graycore.f90
rename to src/gray_core.f90
index 89cd989..81c1dcf 100644
--- a/src/graycore.f90
+++ b/src/gray_core.f90
@@ -1,4 +1,4 @@
-module graycore
+module gray_core
   use const_and_precisions, only : wp_
   implicit none
 
@@ -2238,4 +2238,4 @@ bb: do
 !    write(usumm,*) ''
   end subroutine print_finals
 
-end module graycore
+end module gray_core
diff --git a/src/gray_jetto1beam.f90 b/src/gray_jetto1beam.f90
index 6238b92..e2362cb 100644
--- a/src/gray_jetto1beam.f90
+++ b/src/gray_jetto1beam.f90
@@ -3,7 +3,7 @@ subroutine gray_jetto1beam(ijetto, mr, mz, r, z, psin, psia, rax, zax, &
     p0mw, alphain, betain, dpdv, jcd, pabs, icd, error)
   use const_and_precisions, only: wp_
   use gray_params,          only: gray_parameters, gray_data, gray_results
-  use graycore,             only: gray_main
+  use gray_core,            only: gray_main
 
   implicit none
 
diff --git a/src/gray_params.f90 b/src/gray_params.f90
index c4a21f9..050b5c4 100644
--- a/src/gray_params.f90
+++ b/src/gray_params.f90
@@ -116,7 +116,7 @@ module gray_params
     real(wp_), allocatable :: jcd(:)  ! Driven current density
   end type
 
-  ! Global variables exposed for graycore
+  ! Global variables exposed for gray_core
   integer, save :: iequil, iprof, ipol
   integer, save :: iwarm, ilarm, imx, ieccd
   integer, save :: igrad, idst, ipass
diff --git a/src/main.f90 b/src/main.f90
index aa9b7c5..797a0c1 100644
--- a/src/main.f90
+++ b/src/main.f90
@@ -1,6 +1,6 @@
 program main
   use const_and_precisions, only : wp_, one, zero
-  use graycore,             only : gray_main
+  use gray_core,            only : gray_main
   use gray_params,          only : gray_parameters, gray_data, gray_results, &
                                    read_parameters, params_set_globals => set_globals
   implicit none
@@ -343,7 +343,7 @@ contains
     use beamdata,             only : init_btr, dealloc_beam
     use pec,                  only : pec_init, postproc_profiles, dealloc_pec, &
                                      rhop_tab, rhot_tab
-    use graycore,             only : print_headers, print_finals, print_pec, &
+    use gray_core,            only : print_headers, print_finals, print_pec, &
                                      print_bres, print_prof, print_maps, &
                                      print_surfq
     implicit none