diff --git a/C/ *Minibuf-7* b/C/ *Minibuf-7*
new file mode 100644
index 000000000..d8eacd145
--- /dev/null
+++ b/C/ *Minibuf-7*	
@@ -0,0 +1 @@
+M-x 
\ No newline at end of file
diff --git a/C/cdmgr.c b/C/cdmgr.c
index 8e50c251a..9f62b5f31 100644
--- a/C/cdmgr.c
+++ b/C/cdmgr.c
@@ -2524,6 +2524,10 @@ static Int p_owner_file(USES_REGS1) { /* '$owner_file'(+P,M,F)	 */
     UNLOCKPE(48, pe);
     return FALSE;
   }
+ if (is_system(pe) || is_foreign(pe) ) { 
+   UNLOCKPE(48, pe);
+    return FALSE;
+ } 
   owner = pe->src.OwnerFile;
   UNLOCKPE(49, pe);
   if (owner == AtomNil)
diff --git a/H/Yatom.h b/H/Yatom.h
index 3cdffe2eb..e0b055073 100755
--- a/H/Yatom.h
+++ b/H/Yatom.h
@@ -554,6 +554,7 @@ typedef uint64_t pred_flags_t;
 #define StatePredFlags (InUsePredFlag|CountPredFlag|SpiedPredFlag|IndexedPredFlag )
 #define is_system(pe) (pe->PredFlags & SystemPredFlags)
 #define is_dynamic(pe) (pe->PredFlags & DynamicPredFlag)
+#define is_foreign(pe) (pe->PredFlags & ForeignPredFlags)
 #define is_static(pe) (pe->PredFlags & CompiledPredFlag)
 #define is_logupd(pe) (pe->PredFlags & LogUpdatePredFlag)
 #ifdef TABLING