diff --git a/src/utils/os.h b/src/utils/os.h
index 77250d6..8913854 100644
--- a/src/utils/os.h
+++ b/src/utils/os.h
@@ -247,6 +247,13 @@
 int os_file_exists(const char *fname);
 
 /**
+ * os_fsync - Sync a file's (for a given stream) state with storage device
+ * @stream: the stream to be flushed
+ * Returns: 0 if the operation succeeded or -1 on failure
+ */
+int os_fsync(FILE *stream);
+
+/**
  * os_zalloc - Allocate and zero memory
  * @size: Number of bytes to allocate
  * Returns: Pointer to allocated and zeroed memory or %NULL on failure
diff --git a/src/utils/os_internal.c b/src/utils/os_internal.c
index 77733ad..b8fb2db 100644
--- a/src/utils/os_internal.c
+++ b/src/utils/os_internal.c
@@ -243,6 +243,12 @@
 }
 
 
+int os_fsync(FILE *stream)
+{
+	return 0;
+}
+
+
 void * os_zalloc(size_t size)
 {
 	void *n = os_malloc(size);
diff --git a/src/utils/os_none.c b/src/utils/os_none.c
index 83fe025..96d243d 100644
--- a/src/utils/os_none.c
+++ b/src/utils/os_none.c
@@ -102,6 +102,12 @@
 }
 
 
+int os_fsync(FILE *stream)
+{
+	return 0;
+}
+
+
 void * os_zalloc(size_t size)
 {
 	return NULL;
diff --git a/src/utils/os_unix.c b/src/utils/os_unix.c
index e0c1125..ac73f7a 100644
--- a/src/utils/os_unix.c
+++ b/src/utils/os_unix.c
@@ -415,6 +415,14 @@
 }
 
 
+int os_fsync(FILE *stream)
+{
+	if (!fflush(stream))
+		return fsync(fileno(stream));
+	return -1;
+}
+
+
 #ifndef WPA_TRACE
 void * os_zalloc(size_t size)
 {
diff --git a/src/utils/os_win32.c b/src/utils/os_win32.c
index 296ea13..890abf4 100644
--- a/src/utils/os_win32.c
+++ b/src/utils/os_win32.c
@@ -216,6 +216,24 @@
 }
 
 
+int os_fsync(FILE *stream)
+{
+	HANDLE hFile;
+
+	if (stream == NULL)
+		return -1;
+
+	hFile = _get_osfhandle(_fileno(stream));
+	if (hFile == INVALID_HANDLE_VALUE)
+		return -1;
+
+	if (!FlushFileBuffers(hFile))
+		return -1;
+
+	return 0;
+}
+
+
 void * os_zalloc(size_t size)
 {
 	return calloc(1, size);
diff --git a/wpa_supplicant/config_file.c b/wpa_supplicant/config_file.c
index ae34f10..aeea70c 100644
--- a/wpa_supplicant/config_file.c
+++ b/wpa_supplicant/config_file.c
@@ -1353,6 +1353,8 @@
 	}
 #endif /* CONFIG_NO_CONFIG_BLOBS */
 
+	os_fsync(f);
+
 	fclose(f);
 
 	if (tmp_name) {