diff --git a/src/fpm.f90 b/src/fpm.f90
index 9e82b91d97..50d39a8842 100644
--- a/src/fpm.f90
+++ b/src/fpm.f90
@@ -21,10 +21,12 @@ module fpm
 use fpm_manifest, only : get_package_data, package_config_t
 use fpm_meta, only : resolve_metapackages
 use fpm_error, only : error_t, fatal_error, fpm_stop
-use,intrinsic :: iso_fortran_env, only : stdin=>input_unit,   &
-                                       & stdout=>output_unit, &
-                                       & stderr=>error_unit
+use, intrinsic :: iso_fortran_env, only : stdin => input_unit, &
+                                        & stdout => output_unit, &
+                                        & stderr => error_unit
 use iso_c_binding, only: c_char, c_ptr, c_int, c_null_char, c_associated, c_f_pointer
+use fpm_environment, only: os_is_unix
+
 implicit none
 private
 public :: cmd_build, cmd_run, cmd_clean
@@ -676,27 +678,28 @@ subroutine delete_skip(is_unix)
     end do
 end subroutine delete_skip
 
+!> Delete the build directory including or excluding dependencies.
 subroutine cmd_clean(settings)
-    !> fpm clean called
+    !> Settings for the clean command.
     class(fpm_clean_settings), intent(in) :: settings
-    ! character(len=:), allocatable :: dir
-    ! type(string_t), allocatable :: files(:)
-    character(len=1) :: response
+
+    character :: user_response
+
     if (is_dir('build')) then
-        ! remove the entire build directory
+        ! Remove the entire build directory
         if (settings%clean_call) then
-            call os_delete_dir(settings%is_unix, 'build')
-            return
+            call os_delete_dir(os_is_unix(), 'build'); return
         end if
-        ! remove the build directory but skip dependencies
+
+        ! Remove the build directory but skip dependencies
         if (settings%clean_skip) then
-            call delete_skip(settings%is_unix)
-            return
+            call delete_skip(os_is_unix()); return
         end if
-        ! prompt to remove the build directory but skip dependencies
+
+        ! Prompt to remove the build directory but skip dependencies
         write(stdout, '(A)', advance='no') "Delete build, excluding dependencies (y/n)? "
-        read(stdin, '(A1)') response
-        if (lower(response) == 'y') call delete_skip(settings%is_unix)
+        read(stdin, '(A1)') user_response
+        if (lower(user_response) == 'y') call delete_skip(os_is_unix())
     else
         write (stdout, '(A)') "fpm: No build directory found."
     end if
diff --git a/src/fpm_command_line.f90 b/src/fpm_command_line.f90
index f1ced79308..306b79a535 100644
--- a/src/fpm_command_line.f90
+++ b/src/fpm_command_line.f90
@@ -23,7 +23,7 @@
 !> ``fpm-help`` and ``fpm --list`` help pages below to make sure the help output
 !> is complete and consistent as well.
 module fpm_command_line
-use fpm_environment,  only : get_os_type, get_env, os_is_unix, &
+use fpm_environment,  only : get_os_type, get_env, &
                              OS_UNKNOWN, OS_LINUX, OS_MACOS, OS_WINDOWS, &
                              OS_CYGWIN, OS_SOLARIS, OS_FREEBSD, OS_OPENBSD
 use M_CLI2,           only : set_args, lget, sget, unnamed, remaining, specified
@@ -112,10 +112,8 @@ module fpm_command_line
 end type
 
 type, extends(fpm_cmd_settings)   :: fpm_clean_settings
-    logical                       :: is_unix
-    character(len=:), allocatable :: calling_dir  ! directory clean called from
-    logical                       :: clean_skip=.false.
-    logical                       :: clean_call=.false.
+    logical                       :: clean_skip = .false.
+    logical                       :: clean_call = .false.
 end type
 
 type, extends(fpm_build_settings) :: fpm_publish_settings
@@ -217,7 +215,6 @@ subroutine get_command_line_settings(cmd_settings)
         character(len=4096)           :: cmdarg
         integer                       :: i
         integer                       :: os
-        logical                       :: is_unix
         type(fpm_install_settings), allocatable :: install_settings
         type(version_t) :: version
         character(len=:), allocatable :: common_args, compiler_args, run_args, working_dir, &
@@ -243,7 +240,6 @@ subroutine get_command_line_settings(cmd_settings)
             case (OS_UNKNOWN); os_type =  "OS Type:     Unknown"
             case default     ; os_type =  "OS Type:     UNKNOWN"
         end select
-        is_unix = os_is_unix(os)
 
         ! Get current release version
         version = fpm_version()
@@ -588,7 +584,7 @@ subroutine get_command_line_settings(cmd_settings)
             & build_tests=.true., &
             & name=names, &
             & runner=val_runner, &
-            & verbose=lget('verbose') )
+            & verbose=lget('verbose'))
 
         case('update')
             call set_args(common_args // ' --fetch-only F --clean F', &
@@ -613,10 +609,8 @@ subroutine get_command_line_settings(cmd_settings)
             allocate(fpm_clean_settings :: cmd_settings)
             call get_current_directory(working_dir, error)
             cmd_settings=fpm_clean_settings( &
-            &   is_unix=is_unix,             &
-            &   calling_dir=working_dir,     &
             &   clean_skip=lget('skip'),     &
-                clean_call=lget('all'))
+            &   clean_call=lget('all'))
 
         case('publish')
             call set_args(common_args // compiler_args //'&