diff --git a/lkql_checker/src/gnatcheck-compiler.adb b/lkql_checker/src/gnatcheck-compiler.adb
index b8f6e8d4b..8c2ffc598 100644
--- a/lkql_checker/src/gnatcheck-compiler.adb
+++ b/lkql_checker/src/gnatcheck-compiler.adb
@@ -1781,9 +1781,9 @@ package body Gnatcheck.Compiler is
          Args (Num_Args) := new String'("--target=codepeer");
       end if;
 
-      if Process_Num > 1 then
+      if Arg.Jobs.Get > 1 then
          Num_Args := @ + 1;
-         Args (Num_Args) := new String'("-j" & Image (Process_Num));
+         Args (Num_Args) := new String'("-j" & Image (Arg.Jobs.Get));
       end if;
 
       if Prj /= "" then
diff --git a/lkql_checker/src/gnatcheck-options.adb b/lkql_checker/src/gnatcheck-options.adb
index 8988f6e1d..7b3fc9eab 100644
--- a/lkql_checker/src/gnatcheck-options.adb
+++ b/lkql_checker/src/gnatcheck-options.adb
@@ -1,5 +1,7 @@
 with Gnatcheck.Output; use Gnatcheck.Output;
 
+with System.Multiprocessors;
+
 package body Gnatcheck.Options is
    procedure Warning (Self : in out Gnatcheck_Error_Handler; Msg : String) is
    begin
@@ -11,4 +13,18 @@ package body Gnatcheck.Options is
       Error (Msg);
    end Error;
 
+   ------------------
+   -- Jobs_Convert --
+   ------------------
+
+   function Jobs_Convert (Arg : String) return Natural is
+      Value : constant Natural := Natural'Value (Arg);
+   begin
+      if Value = 0 then
+         return Natural (System.Multiprocessors.Number_Of_CPUs);
+      else
+         return Value;
+      end if;
+   end Jobs_Convert;
+
 end Gnatcheck.Options;
diff --git a/lkql_checker/src/gnatcheck-options.ads b/lkql_checker/src/gnatcheck-options.ads
index bdc62e472..56e3e3a38 100644
--- a/lkql_checker/src/gnatcheck-options.ads
+++ b/lkql_checker/src/gnatcheck-options.ads
@@ -122,14 +122,6 @@ package Gnatcheck.Options is
    Files_Switch_Used : Boolean := False;
    --  True if the files= switch was used
 
-   Process_Num : Natural := 1;
-   --  The maximal number of cores used
-   --  -jN
-
-   J_Specified : Boolean := False;
-   --  True if the -jN option was given. This is used to distinguish -j0 on a
-   --  uniprocessor from no -j switch.
-
    ----------------------------------------
    -- Flags computed from other settings --
    ----------------------------------------
@@ -248,6 +240,8 @@ package Gnatcheck.Options is
    procedure Warning (Self : in out Gnatcheck_Error_Handler; Msg : String);
    procedure Error (Self : in out Gnatcheck_Error_Handler; Msg : String);
 
+   function Jobs_Convert (Arg : String) return Natural;
+
    package Arg is
       Parser : Argument_Parser := Create_Argument_Parser
         (Help                 => "GNATcheck help",
@@ -432,6 +426,15 @@ package Gnatcheck.Options is
          Default_Val => Null_Unbounded_String,
          Help        => "do not process sources listed in filename");
 
+      package Jobs is new Parse_Option
+        (Parser      => Parser,
+         Short       => "-j",
+         Name        => "Jobs",
+         Arg_Type    => Natural,
+         Default_Val => 1,
+         Convert     => Jobs_Convert,
+         Help        => "the maximal number of processes");
+
       function Quiet_Mode return Boolean is (Quiet.Get or else Brief.Get);
 
       function Short_Report return Boolean is (Brief.Get or else Short.Get);
diff --git a/lkql_checker/src/gnatcheck-projects.adb b/lkql_checker/src/gnatcheck-projects.adb
index 0d2539eee..ea30096e3 100644
--- a/lkql_checker/src/gnatcheck-projects.adb
+++ b/lkql_checker/src/gnatcheck-projects.adb
@@ -58,8 +58,6 @@ with GNATCOLL.Traces;
 
 with Rule_Commands; use Rule_Commands;
 
-with System.Multiprocessors;
-
 package body Gnatcheck.Projects is
 
    subtype Unbounded_String is Ada.Strings.Unbounded.Unbounded_String;
@@ -1118,7 +1116,6 @@ package body Gnatcheck.Projects is
               "m? files= a "                &
               "vP! "                        &   --  project-specific options
               "-kp-version= "               &
-              "j! "                         &
               "o= "                         &
               "ox= "                        &
               "l log "                      &
@@ -1184,27 +1181,6 @@ package body Gnatcheck.Projects is
                   end if;
                end if;
 
-            when 'j' =>
-               if Full_Switch (Parser => Parser) = "j"
-                 and then not First_Pass
-               then
-                  begin
-                     J_Specified := True;
-                     Process_Num :=
-                       Natural'Value (Parameter (Parser => Parser));
-
-                     if Process_Num = 0 then
-                        Process_Num :=
-                          Positive (System.Multiprocessors.Number_Of_CPUs);
-                     end if;
-                  exception
-                     when Constraint_Error =>
-                        Error ("Wrong Parameter of '-j' option: " &
-                               Parameter (Parser => Parser));
-                        raise Parameter_Error;
-                  end;
-               end if;
-
             when 'l' =>
                if not First_Pass then
                   if Full_Switch (Parser => Parser) = "l" then
diff --git a/lkql_checker/src/gnatcheck_main.adb b/lkql_checker/src/gnatcheck_main.adb
index 56894b2c7..e5e1e608d 100644
--- a/lkql_checker/src/gnatcheck_main.adb
+++ b/lkql_checker/src/gnatcheck_main.adb
@@ -158,6 +158,7 @@ procedure Gnatcheck_Main is
       File          : Ada.Text_IO.File_Type;
       Status        : Boolean;
       Total_Jobs    : Natural;
+      Process_Num   : Natural := Arg.Jobs.Get;
    begin
       --  Compute number of files