diff --git a/lkql_checker/doc/gnatcheck_rm/using_gnatcheck.rst b/lkql_checker/doc/gnatcheck_rm/using_gnatcheck.rst
index c68902869..1979fb117 100644
--- a/lkql_checker/doc/gnatcheck_rm/using_gnatcheck.rst
+++ b/lkql_checker/doc/gnatcheck_rm/using_gnatcheck.rst
@@ -813,7 +813,7 @@ registered for this version, via the switch ``--kp-version``. For example:
 
 .. code-block:: none
 
-   gnatkp -Pproject --kp-version=21.2
+  gnatkp -Pproject --kp-version=21.2 --target=<my_target> --RTS=<my_runtime>
 
 will run all detectors relevant to GNAT Pro 21.2 on all files in the
 project. The list of detectors will be displayed as info messages, and will
@@ -826,14 +826,14 @@ additionally the ``-h`` switch, e.g.:
 
 .. code-block:: none
 
-   gnatkp --kp-version=21.2 -h
+  gnatkp --kp-version=21.2 -h --target=<my_target> --RTS=<my_runtime>
 
 You can also combine the ``--kp-version`` switch with the ``--target`` switch
 to filter out detectors not relevant for your target, e.g:
 
 .. code-block:: none
 
-   gnatkp -Pproject --kp-version=21.2 --target=powerpc-elf
+  gnatkp -Pproject --kp-version=21.2 --target=powerpc-elf --RTS=<my_runtime>
 
 will only enable detectors relevant to GNAT Pro 21.2 and to the ``powerpc-elf``
 target.
@@ -846,7 +846,7 @@ using the switch ``-rules``:
 
 .. code-block:: none
 
-   gnatkp -Pproject -rules +Rkp_xxxx_xxx [+Rkp_xxxx_xxx]
+  gnatkp -Pproject --target=<my_target> --RTS=<my_runtime> -rules +Rkp_xxxx_xxx [+Rkp_xxxx_xxx]
 
 where ``kp_xxxx_xxx`` is the name of a relevant known-problem to detect. You
 can get the list of available detectors via the command ``gnatkp -h``. When
@@ -854,6 +854,12 @@ combined with the ``--kp-version`` and possibly ``--target`` switches,
 ``gnatkp -h`` will only list the detectors relevant to the version
 (and target) specified.
 
+.. attention::
+
+  You must provide explicit target and runtime (either through the command-line
+  or with a provided project file) when running GNATKP to ensure the result
+  soundness.
+
 You can check via the GNAT Tracker interface which known problems are
 relevant to your version of GNAT and your target before deciding which
 known problems may impact you: most known problems are only relevant to a
diff --git a/lkql_checker/src/gnatcheck-projects.adb b/lkql_checker/src/gnatcheck-projects.adb
index e9a90fd05..4ee5255b6 100644
--- a/lkql_checker/src/gnatcheck-projects.adb
+++ b/lkql_checker/src/gnatcheck-projects.adb
@@ -499,7 +499,7 @@ package body Gnatcheck.Projects is
             Gnatcheck.Projects.Aggregate.Collect_Aggregated_Projects
               (My_Project.Tree);
 
-            Set_Unbounded_String (Target, String (My_Project.Tree.Target));
+            Target := To_Unbounded_String (String (My_Project.Tree.Target));
          end if;
 
          My_Project.Tree.Update_Sources (Messages => Log);
diff --git a/lkql_checker/src/gnatcheck_main.adb b/lkql_checker/src/gnatcheck_main.adb
index e5e1e608d..d4a5a25eb 100644
--- a/lkql_checker/src/gnatcheck_main.adb
+++ b/lkql_checker/src/gnatcheck_main.adb
@@ -468,11 +468,18 @@ begin
 
    Process_Rule_Options;
 
-   --  Force some switches for gnatkp
+   --  Force some switches and perform some checks for gnatkp
 
    if Gnatkp_Mode then
       Max_Diagnoses  := 0;
       Log_Mode       := False;
+
+      if Target = Null_Unbounded_String
+        or else RTS_Path = Null_Unbounded_String
+      then
+         Error ("missing explicit target and/or runtime");
+         OS_Exit (E_Error);
+      end if;
    end if;
 
    Set_Log_File;
@@ -518,9 +525,7 @@ begin
    Gnatcheck.Rules.Rule_Table.Clean_Up;
    Close_Log_File;
 
-   OS_Exit (if Tool_Failures /= 0
-              or else
-               Detected_Internal_Error /= 0
+   OS_Exit (if Tool_Failures /= 0 or else Detected_Internal_Error /= 0
             then                                    E_Error
             elsif Missing_Rule_File_Detected   then E_Missing_Rule_File
             elsif Bad_Rule_Detected            then E_Missing_Rule
diff --git a/testsuite/drivers/gnatcheck_driver.py b/testsuite/drivers/gnatcheck_driver.py
index aeb39e59d..48983222a 100644
--- a/testsuite/drivers/gnatcheck_driver.py
+++ b/testsuite/drivers/gnatcheck_driver.py
@@ -128,6 +128,8 @@ class GnatcheckDriver(BaseDriver):
         - ``label`` (str): An arbitrary label to add at the top of the gnatcheck
           output.
         - ``worker``: Provide a custom worker for the GNATcheck run.
+        - ``gnatkp_autoconfig`` (bool): Whether to automatically configure the
+          target and runtime when running in "gnatkp" mode. Default is True.
 
         - ``jobs`` (int): The number of jobs to forward to the GNATcheck command.
         - ``project`` (str): GPR build file to use (if any).
@@ -263,6 +265,13 @@ def run_one_test(test_data: dict[str, any]) -> None:
             if pre_python:
                 capture_exec_python(pre_python)
 
+            # If the executable is gantkp, we must provide an explicit runtime
+            # and target
+            if exe == "gnatkp" and test_data.get('gnatkp_autoconfig', True):
+                if not self.is_codepeer:
+                    args.append(f"--target={self.env.build.platform}")
+                args.append("--RTS=native")
+
             # Set the codepeer target if needed
             if self.is_codepeer:
                 args.append("--target=codepeer")