diff --git a/include/srv0srv.h b/include/srv0srv.h
index 2f2bc316873..ff82cb2999a 100644
--- a/include/srv0srv.h
+++ b/include/srv0srv.h
@@ -344,11 +344,7 @@ srv_release_threads(
 /*************************************************************************
 The master thread controlling the server. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_master_thread(
 /*==============*/
 			/* out: a dummy parameter */
@@ -430,11 +426,7 @@ srv_release_mysql_thread_if_suspended(
 A thread which wakes up threads whose lock wait may have lasted too long.
 This also prints the info output by various InnoDB monitors. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_lock_timeout_and_monitor_thread(
 /*================================*/
 			/* out: a dummy parameter */
@@ -444,11 +436,7 @@ srv_lock_timeout_and_monitor_thread(
 A thread which prints warnings about semaphore waits which have lasted
 too long. These can be used to track bugs which cause hangs. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_error_monitor_thread(
 /*=====================*/
 			/* out: a dummy parameter */
diff --git a/include/trx0roll.h b/include/trx0roll.h
index 7b450f9da39..25546430ba0 100644
--- a/include/trx0roll.h
+++ b/include/trx0roll.h
@@ -107,11 +107,7 @@ transaction already was committed, then we clean up a possible insert
 undo log. If the transaction was not yet committed, then we roll it back.
 Note: this is done in a background thread. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 trx_rollback_or_clean_all_without_sess(
 /*===================================*/
 			/* out: a dummy parameter */
diff --git a/include/univ.i b/include/univ.i
index 5b294ae0769..c5e87e468c6 100644
--- a/include/univ.i
+++ b/include/univ.i
@@ -273,6 +273,18 @@ it is read or written. */
 /* Compile-time constant of the given array's size. */
 #define UT_ARR_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
+/* The return type from a thread's start function differs between Unix and
+Windows, so define a typedef for it and a macro to use at the end of such
+functions. */
+
+#ifdef __WIN__
+typedef ulint os_thread_ret_t;
+#define OS_THREAD_DUMMY_RETURN return(0)
+#else
+typedef void* os_thread_ret_t;
+#define OS_THREAD_DUMMY_RETURN return(NULL)
+#endif
+
 #include <stdio.h>
 #include "ut0dbg.h"
 #include "ut0ut.h"
diff --git a/srv/srv0srv.c b/srv/srv0srv.c
index cacaebaea2b..83cdcaa271b 100644
--- a/srv/srv0srv.c
+++ b/srv/srv0srv.c
@@ -1819,11 +1819,7 @@ srv_export_innodb_status(void)
 A thread which wakes up threads whose lock wait may have lasted too long.
 This also prints the info output by various InnoDB monitors. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_lock_timeout_and_monitor_thread(
 /*================================*/
 			/* out: a dummy parameter */
@@ -1995,22 +1991,15 @@ exit_func:
 	thread should always use that to exit and not use return() to exit. */
 
 	os_thread_exit(NULL);
-#ifndef __WIN__
-	return(NULL);
-#else
-	return(0);
-#endif
+
+	OS_THREAD_DUMMY_RETURN;
 }
 
 /*************************************************************************
 A thread which prints warnings about semaphore waits which have lasted
 too long. These can be used to track bugs which cause hangs. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_error_monitor_thread(
 /*=====================*/
 			/* out: a dummy parameter */
@@ -2092,11 +2081,7 @@ loop:
 
 	os_thread_exit(NULL);
 
-#ifndef __WIN__
-	return(NULL);
-#else
-	return(0);
-#endif
+	OS_THREAD_DUMMY_RETURN;
 }
 
 /***********************************************************************
@@ -2141,11 +2126,7 @@ srv_wake_master_thread(void)
 /*************************************************************************
 The master thread controlling the server. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 srv_master_thread(
 /*==============*/
 			/* out: a dummy parameter */
@@ -2590,10 +2571,6 @@ suspend_thread:
 
 	os_thread_exit(NULL);
 
-#ifndef __WIN__
-	return(NULL);				/* Not reached */
-#else
-	return(0);
-#endif
+	OS_THREAD_DUMMY_RETURN;
 }
 #endif /* !UNIV_HOTBACKUP */
diff --git a/srv/srv0start.c b/srv/srv0start.c
index 6b55092a068..da2deac123d 100644
--- a/srv/srv0start.c
+++ b/srv/srv0start.c
@@ -426,11 +426,7 @@ srv_parse_log_group_home_dirs(
 I/o-handler thread function. */
 static
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 io_handler_thread(
 /*==============*/
 	void*	arg)
@@ -459,11 +455,7 @@ io_handler_thread(
 
 	os_thread_exit(NULL);
 
-#ifndef __WIN__
-	return(NULL);				/* Not reached */
-#else
-	return(0);
-#endif
+	OS_THREAD_DUMMY_RETURN;
 }
 #endif /* !UNIV_HOTBACKUP */
 
diff --git a/trx/trx0roll.c b/trx/trx0roll.c
index fd733ef5fb8..af74cfe9032 100644
--- a/trx/trx0roll.c
+++ b/trx/trx0roll.c
@@ -391,11 +391,7 @@ transaction already was committed, then we clean up a possible insert
 undo log. If the transaction was not yet committed, then we roll it back.
 Note: this is done in a background thread. */
 
-#ifndef __WIN__
-void*
-#else
-ulint
-#endif
+os_thread_ret_t
 trx_rollback_or_clean_all_without_sess(
 /*===================================*/
 			/* out: a dummy parameter */
@@ -576,13 +572,7 @@ leave_function:
 
 	os_thread_exit(NULL);
 
-	/* The following is dummy code to keep the compiler happy: */
-
-#ifndef __WIN__
-	return(NULL);
-#else
-	return(0);
-#endif
+	OS_THREAD_DUMMY_RETURN;
 }
 
 /***********************************************************************