diff --git a/gdbinit.py b/gdbinit.py
index e55b99fe5..c864774e7 100644
--- a/gdbinit.py
+++ b/gdbinit.py
@@ -162,6 +162,16 @@ def init_logger():
 
 
 def main() -> None:
+    if "pwndbg" in sys.modules:
+        print(
+            "Detected double-loading of Pwndbg (likely from both .gdbinit and the Pwndbg portable build)."
+        )
+        print(
+            "To fix this, please remove the line 'source your-path/gdbinit.py' from your .gdbinit file."
+        )
+        sys.stdout.flush()
+        os._exit(1)
+
     profiler = cProfile.Profile()
 
     start_time = None
diff --git a/lldbinit.py b/lldbinit.py
index 94698511c..f9fcb31fa 100644
--- a/lldbinit.py
+++ b/lldbinit.py
@@ -125,6 +125,11 @@ def skip_venv(src_root) -> bool:
 
 
 def main(debugger: lldb.SBDebugger, major: int, minor: int, debug: bool = False) -> None:
+    if "pwndbg" in sys.modules:
+        print("Detected double-loading of Pwndbg.")
+        print("This should not happen. Please report this issue if you're not sure how to fix it.")
+        sys.exit(1)
+
     profiler = cProfile.Profile()
 
     start_time = None