diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 29b51b9d17a..342a1d3b89f 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -719,6 +719,26 @@ bool end_active_trans(THD *thd);
 int end_trans(THD *thd, enum enum_mysql_completiontype completion);
 
 Item *negate_expression(THD *thd, Item *expr);
+
+/* log.cc */
+int vprint_msg_to_log(enum loglevel level, const char *format, va_list args);
+void sql_print_error(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
+void sql_print_warning(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
+void sql_print_information(const char *format, ...)
+  ATTRIBUTE_FORMAT(printf, 1, 2);
+typedef void (*sql_print_message_func)(const char *format, ...)
+  ATTRIBUTE_FORMAT(printf, 1, 2);
+extern sql_print_message_func sql_print_message_handlers[];
+
+int error_log_print(enum loglevel level, const char *format,
+                    va_list args);
+
+bool slow_log_print(THD *thd, const char *query, uint query_length,
+                    time_t query_start_arg);
+
+bool general_log_print(THD *thd, enum enum_server_command command,
+                       const char *format,...);
+
 #include "sql_class.h"
 #include "sql_acl.h"
 #include "tztime.h"
@@ -1620,25 +1640,6 @@ bool init_errmessage(void);
 #endif /* MYSQL_SERVER */
 void sql_perror(const char *message);
 
-
-int vprint_msg_to_log(enum loglevel level, const char *format, va_list args);
-void sql_print_error(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
-void sql_print_warning(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
-void sql_print_information(const char *format, ...)
-  ATTRIBUTE_FORMAT(printf, 1, 2);
-typedef void (*sql_print_message_func)(const char *format, ...)
-  ATTRIBUTE_FORMAT(printf, 1, 2);
-extern sql_print_message_func sql_print_message_handlers[];
-
-int error_log_print(enum loglevel level, const char *format,
-                    va_list args);
-
-bool slow_log_print(THD *thd, const char *query, uint query_length,
-                    time_t query_start_arg);
-
-bool general_log_print(THD *thd, enum enum_server_command command,
-                       const char *format,...);
-
 bool fn_format_relative_to_data_home(char * to, const char *name,
 				     const char *dir, const char *extension);
 #ifdef MYSQL_SERVER
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 52feee47499..b9aa6ce66a2 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -1569,11 +1569,27 @@ public:
     proc_info = old_msg;
     pthread_mutex_unlock(&mysys_var->mutex);
   }
+
+  static inline void safe_time(time_t *t)
+  {
+    /**
+       Wrapper around time() which retries on error (-1)
+
+       @details
+       This is needed because, despite the documentation, time() may fail
+       in some circumstances.  Here we retry time() until it succeeds, and
+       log the failure so that performance problems related to this can be
+       identified.
+    */
+    while(unlikely(time(t) == ((time_t) -1)))
+      sql_print_information("time() failed with %d", errno);
+  }
+
   inline time_t query_start() { query_start_used=1; return start_time; }
-  inline void	set_time()    { if (user_time) start_time=time_after_lock=user_time; else time_after_lock=time(&start_time); }
-  inline void	end_time()    { time(&start_time); }
+  inline void	set_time()    { if (user_time) start_time=time_after_lock=user_time; else { safe_time(&start_time); time_after_lock= start_time; }}
+  inline void	end_time()    { safe_time(&start_time); }
   inline void	set_time(time_t t) { time_after_lock=start_time=user_time=t; }
-  inline void	lock_time()   { time(&time_after_lock); }
+  inline void	lock_time()   { safe_time(&time_after_lock); }
   inline ulonglong found_rows(void)
   {
     return limit_found_rows;