diff --git a/src/net.c b/src/net.c
index 169c0a99..addc0a47 100644
--- a/src/net.c
+++ b/src/net.c
@@ -86,7 +86,7 @@ static void net__print_error(int log, const char *format_str)
 
 #ifdef WIN32
 	FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
-			NULL, WSAGetLastError(), LANG_NEUTRAL, &buf, 0, NULL);
+			NULL, WSAGetLastError(), LANG_NEUTRAL, (LPTSTR)&buf, 0, NULL);
 
 	log__printf(NULL, log, format_str, buf);
 	LocalFree(buf);
diff --git a/src/security.c b/src/security.c
index 7779ca55..20b30627 100644
--- a/src/security.c
+++ b/src/security.c
@@ -33,7 +33,7 @@ void LIB_ERROR(void)
 #ifdef WIN32
 	char *buf;
 	FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_STRING,
-			NULL, GetLastError(), LANG_NEUTRAL, &buf, 0, NULL);
+			NULL, GetLastError(), LANG_NEUTRAL, (LPTSTR)&buf, 0, NULL);
 	log__printf(NULL, MOSQ_LOG_ERR, "Load error: %s", buf);
 	LocalFree(buf);
 #else
diff --git a/src/service.c b/src/service.c
index 05bee0c5..08099aa5 100644
--- a/src/service.c
+++ b/src/service.c
@@ -32,7 +32,7 @@ static void print_error(void)
 	char *buf;
 
 	FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
-		NULL, GetLastError(), LANG_NEUTRAL, &buf, 0, NULL);
+		NULL, GetLastError(), LANG_NEUTRAL, (LPTSTR)&buf, 0, NULL);
 
 	fprintf(stderr, "Error: %s\n", buf);
 	LocalFree(buf);