diff --git a/dbug/dbug.c b/dbug/dbug.c
index 9ec8044..c63db2e 100644
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@@ -272,6 +272,9 @@ static void PushState(CODE_STATE *cs);
 static void FreeState (CODE_STATE *cs, int free_state);
         /* Test for tracing enabled */
 static int DoTrace(CODE_STATE *cs);
+        /* Check keyword */
+static BOOLEAN DBUGKeyword(CODE_STATE *cs, const char *keyword, int strict);
+
 /*
   return values of DoTrace.
   Can also be used as bitmask: ret & DO_TRACE
@@ -1267,7 +1270,7 @@ void _db_doprnt_(const char *format,...)
 
   if (!cs->locked)
     pthread_mutex_lock(&THR_LOCK_dbug);
-  if (_db_keyword_(cs, cs->u_keyword, 0))
+  if (DBUGKeyword(cs, cs->u_keyword, 0))
   {
     int save_errno=errno;
     DoPrefix(cs, cs->u_line);
@@ -1326,7 +1329,7 @@ void _db_dump_(uint _line_, const char *keyword,
 
   if (!cs->locked)
     pthread_mutex_lock(&THR_LOCK_dbug);
-  if (_db_keyword_(cs, keyword, 0))
+  if (DBUGKeyword(cs, keyword, 0))
   {
     DoPrefix(cs, _line_);
     if (TRACING)
@@ -1705,8 +1708,23 @@ FILE *_db_fp_(void)
 
 BOOLEAN _db_keyword_(CODE_STATE *cs, const char *keyword, int strict)
 {
+  BOOLEAN res;
+  get_code_state_or_return FALSE;
+
+  if (!cs->locked)
+    pthread_mutex_lock(&THR_LOCK_dbug);
+
+  res= DBUGKeyword(cs, keyword, strict);
+
+  if (!cs->locked)
+    pthread_mutex_unlock(&THR_LOCK_dbug);
+
+  return res;
+}
+
+static BOOLEAN DBUGKeyword(CODE_STATE *cs, const char *keyword, int strict)
+{
   int match= strict ? INCLUDE : INCLUDE|MATCHED;
-  get_code_state_if_not_set_or_return FALSE;
 
   return (DEBUGGING && DoTrace(cs) & DO_TRACE &&
           InList(cs->stack->keywords, keyword, strict) & match);
diff --git a/mysql-test/r/debug.result b/mysql-test/r/debug.result
new file mode 100644
index 0000000..a388675
--- /dev/null
+++ b/mysql-test/r/debug.result
@@ -0,0 +1,22 @@
+CREATE PROCEDURE p1 ()
+begin
+set @a = 0;
+while @a < 100 do
+SET GLOBAL debug='';
+SET debug='';
+SET GLOBAL debug='+dkalle';
+SET debug=@tmp;
+set @a = @a + 1;
+end while;
+end;|
+CREATE PROCEDURE p2 ()
+begin
+set @a = 0;
+while @a < 100 do
+select @@debug;
+set @a = @a + 1;
+end while;
+end;|
+drop procedure p1;
+drop procedure p2;
+Resetting global.debug to initial state
diff --git a/mysql-test/t/debug.test b/mysql-test/t/debug.test
new file mode 100644
index 0000000..4165a92
--- /dev/null
+++ b/mysql-test/t/debug.test
@@ -0,0 +1,160 @@
+#
+# We need the debug
+#
+--source include/have_debug.inc
+
+#
+# Skip embedded
+#
+--source include/not_embedded.inc
+
+#
+# test that SET @@global.debug is thread-safe
+#   as in don't crash :-)
+#
+let $save_debug=`select @@debug`;
+
+--disable_query_log
+--disable_result_log
+--eval set @tmp='$save_debug';
+--enable_query_log
+--enable_result_log
+
+delimiter |;
+CREATE PROCEDURE p1 ()
+begin
+  set @a = 0;
+  while @a < 100 do
+    SET GLOBAL debug='';
+    SET debug='';
+    SET GLOBAL debug='+dkalle';
+    SET debug=@tmp;
+    set @a = @a + 1;
+  end while;
+end;|
+CREATE PROCEDURE p2 ()
+begin
+  set @a = 0;
+  while @a < 100 do
+    select @@debug;
+    set @a = @a + 1;
+  end while;
+end;|
+delimiter ;|
+
+connect (con0,localhost,root,,);
+connect (con1,localhost,root,,);
+connect (con2,localhost,root,,);
+connect (con3,localhost,root,,);
+connect (con4,localhost,root,,);
+connect (con5,localhost,root,,);
+connect (con6,localhost,root,,);
+connect (con7,localhost,root,,);
+connect (con8,localhost,root,,);
+connect (con9,localhost,root,,);
+connect (con10,localhost,root,,);
+connect (con11,localhost,root,,);
+connect (con12,localhost,root,,);
+connect (con13,localhost,root,,);
+connect (con14,localhost,root,,);
+connect (con15,localhost,root,,);
+connect (con16,localhost,root,,);
+connect (con17,localhost,root,,);
+connect (con18,localhost,root,,);
+connect (con19,localhost,root,,);
+
+--disable_query_log
+--disable_result_log
+--connection con0
+send call p1();
+--connection con1
+send call p2();
+--connection con2
+send call p1();
+--connection con3
+send call p2();
+--connection con4
+send call p1();
+--connection con5
+send call p2();
+--connection con6
+send call p1();
+--connection con7
+send call p2();
+--connection con8
+send call p1();
+--connection con9
+send call p2();
+--connection con10
+send call p1();
+--connection con11
+send call p2();
+--connection con12
+send call p1();
+--connection con13
+send call p2();
+--connection con14
+send call p1();
+--connection con15
+send call p2();
+--connection con16
+send call p1();
+--connection con17
+send call p2();
+--connection con18
+send call p1();
+--connection con19
+send call p2();
+
+--connection con0
+reap;
+--connection con1
+reap;
+--connection con2
+reap;
+--connection con3
+reap;
+--connection con4
+reap;
+--connection con5
+reap;
+--connection con6
+reap;
+--connection con7
+reap;
+--connection con8
+reap;
+--connection con9
+reap;
+--connection con10
+reap;
+--connection con11
+reap;
+--connection con12
+reap;
+--connection con13
+reap;
+--connection con14
+reap;
+--connection con15
+reap;
+--connection con16
+reap;
+--connection con17
+reap;
+--connection con18
+reap;
+--connection con19
+reap;
+--enable_result_log
+--enable_query_log
+
+drop procedure p1;
+drop procedure p2;
+
+--echo Resetting global.debug to initial state
+--disable_query_log
+--disable_result_log
+--eval SET GLOBAL debug='$save_debug';
+--enable_result_log
+--enable_query_log