diff --git a/mysql-test/r/im_life_cycle.result b/mysql-test/r/im_life_cycle.result
index a9f78aea7d3..211a82eb9cf 100644
--- a/mysql-test/r/im_life_cycle.result
+++ b/mysql-test/r/im_life_cycle.result
@@ -74,3 +74,6 @@ START INSTANCE mysqld1,mysqld2,mysqld3;
 ERROR 42000: You have an error in your command syntax. Check the manual that corresponds to your MySQL Instance Manager version for the right syntax to use
 STOP INSTANCE mysqld1,mysqld2,mysqld3;
 ERROR 42000: You have an error in your command syntax. Check the manual that corresponds to your MySQL Instance Manager version for the right syntax to use
+STOP INSTANCE mysqld2;
+ERROR HY000: Cannot stop instance. Perhaps the instance is not started, or was started manually, so IM cannot find the pidfile.
+End of 5.0 tests
diff --git a/mysql-test/t/im_life_cycle.imtest b/mysql-test/t/im_life_cycle.imtest
index 2cbe53a7b28..c3a5fb0a648 100644
--- a/mysql-test/t/im_life_cycle.imtest
+++ b/mysql-test/t/im_life_cycle.imtest
@@ -218,3 +218,11 @@ START INSTANCE mysqld1,mysqld2,mysqld3;
 
 --error ER_SYNTAX_ERROR
 STOP INSTANCE mysqld1,mysqld2,mysqld3;
+
+#
+# Bug #12673: Instance Manager: allows to stop the instance many times
+#
+--error 3001
+STOP INSTANCE mysqld2;
+
+--echo End of 5.0 tests
diff --git a/server-tools/instance-manager/instance.cc b/server-tools/instance-manager/instance.cc
index 39381b457ab..2ed369ba245 100644
--- a/server-tools/instance-manager/instance.cc
+++ b/server-tools/instance-manager/instance.cc
@@ -469,37 +469,38 @@ int Instance::stop()
   struct timespec timeout;
   uint waitchild= (uint)  DEFAULT_SHUTDOWN_DELAY;
 
-  if (options.shutdown_delay_val)
-    waitchild= options.shutdown_delay_val;
-
-  kill_instance(SIGTERM);
-  /* sleep on condition to wait for SIGCHLD */
-
-  timeout.tv_sec= time(NULL) + waitchild;
-  timeout.tv_nsec= 0;
-  if (pthread_mutex_lock(&LOCK_instance))
-    goto err;
-
-  while (options.get_pid() != 0)              /* while server isn't stopped */
+  if (is_running())
   {
-    int status;
+    if (options.shutdown_delay_val)
+      waitchild= options.shutdown_delay_val;
 
-    status= pthread_cond_timedwait(&COND_instance_stopped,
-                                   &LOCK_instance,
-                                   &timeout);
-    if (status == ETIMEDOUT || status == ETIME)
-      break;
+    kill_instance(SIGTERM);
+    /* sleep on condition to wait for SIGCHLD */
+
+    timeout.tv_sec= time(NULL) + waitchild;
+    timeout.tv_nsec= 0;
+    if (pthread_mutex_lock(&LOCK_instance))
+      return ER_STOP_INSTANCE;
+
+    while (options.get_pid() != 0)              /* while server isn't stopped */
+    {
+      int status;
+
+      status= pthread_cond_timedwait(&COND_instance_stopped,
+                                     &LOCK_instance,
+                                     &timeout);
+      if (status == ETIMEDOUT || status == ETIME)
+        break;
+    }
+
+    pthread_mutex_unlock(&LOCK_instance);
+
+    kill_instance(SIGKILL);
+
+    return 0;
   }
 
-  pthread_mutex_unlock(&LOCK_instance);
-
-  kill_instance(SIGKILL);
-
-  return 0;
-
   return ER_INSTANCE_IS_NOT_STARTED;
-err:
-  return ER_STOP_INSTANCE;
 }
 
 #ifdef __WIN__
diff --git a/server-tools/instance-manager/messages.cc b/server-tools/instance-manager/messages.cc
index a9b00b9e01f..d2595638de0 100644
--- a/server-tools/instance-manager/messages.cc
+++ b/server-tools/instance-manager/messages.cc
@@ -48,8 +48,8 @@ static const char *mysqld_error_message(unsigned sql_errno)
   case ER_BAD_INSTANCE_NAME:
     return "Bad instance name. Check that the instance with such a name exists";
   case ER_INSTANCE_IS_NOT_STARTED:
-    return "Cannot stop instance. Perhaps the instance is not started, or was started"
-            "manually, so IM cannot find the pidfile.";
+    return "Cannot stop instance. Perhaps the instance is not started, or was"
+           " started manually, so IM cannot find the pidfile.";
   case ER_INSTANCE_ALREADY_STARTED:
     return "The instance is already started";
   case ER_CANNOT_START_INSTANCE:
@@ -67,7 +67,7 @@ static const char *mysqld_error_message(unsigned sql_errno)
     return "Cannot open log file";
   case ER_GUESS_LOGFILE:
     return "Cannot guess the log filename. Try specifying full log name"
-           "in the instance options";
+           " in the instance options";
   case ER_ACCESS_OPTION_FILE:
     return "Cannot open the option file to edit. Check permissions";
   default: