diff --git a/configure.ac b/configure.ac
index 4cdc1bb6..f6852c13 100644
--- a/configure.ac
+++ b/configure.ac
@@ -93,6 +93,7 @@ AC_CHECK_FUNCS([memchr])
 AC_CHECK_FUNCS([memmove])
 AC_CHECK_FUNCS([memset])
 AC_CHECK_FUNCS([mkdir])
+AC_CHECK_FUNCS([mkstemp])
 AC_CHECK_FUNCS([pow])
 AC_CHECK_FUNCS([setlocale])
 AC_CHECK_FUNCS([sqrt])
diff --git a/src/libespeak-ng/compiledata.c b/src/libespeak-ng/compiledata.c
index aeb554a1..7dd4a4b4 100644
--- a/src/libespeak-ng/compiledata.c
+++ b/src/libespeak-ng/compiledata.c
@@ -1261,7 +1261,7 @@ static int LoadWavefile(FILE *f, const char *fname)
 
 		failed = 0;
 
-#ifdef PLATFORM_POSIX
+#ifdef HAVE_MKSTEMP
 		strcpy(fname_temp, "/tmp/espeakXXXXXX");
 		if ((fd_temp = mkstemp(fname_temp)) >= 0)
 			close(fd_temp);
diff --git a/src/libespeak-ng/readclause.c b/src/libespeak-ng/readclause.c
index a615a68f..d9d12ae6 100644
--- a/src/libespeak-ng/readclause.c
+++ b/src/libespeak-ng/readclause.c
@@ -826,7 +826,7 @@ static espeak_ng_STATUS LoadSoundFile(const char *fname, int index, espeak_ng_ER
 			fclose(f);
 			f = NULL;
 
-#ifdef PLATFORM_POSIX
+#ifdef HAVE_MKSTEMP
 			strcpy(fname_temp, "/tmp/espeakXXXXXX");
 			if ((fd_temp = mkstemp(fname_temp)) >= 0)
 				close(fd_temp);