diff --git a/libmariadb/ma_default.c b/libmariadb/ma_default.c
index e1aeb1c6..6ae7c8e7 100644
--- a/libmariadb/ma_default.c
+++ b/libmariadb/ma_default.c
@@ -27,7 +27,7 @@
 
 #ifdef _WIN32
 #include <io.h>
-#include "Shlwapi.h"
+#include "shlwapi.h"
 
 static const char *ini_exts[]= {"ini", "cnf", 0};
 #define R_OK 4
diff --git a/plugins/auth/sspi_client.c b/plugins/auth/sspi_client.c
index 9d02fce7..e257cd9d 100644
--- a/plugins/auth/sspi_client.c
+++ b/plugins/auth/sspi_client.c
@@ -29,7 +29,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define SECURITY_WIN32
 #include <windows.h>
 #include <sspi.h>
-#include <SecExt.h>
+#include <secext.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/plugins/auth/sspi_common.h b/plugins/auth/sspi_common.h
index 34b8a56a..5538f76e 100644
--- a/plugins/auth/sspi_common.h
+++ b/plugins/auth/sspi_common.h
@@ -29,10 +29,10 @@ POSSIBILITY OF SUCH DAMAGE.
 #define SECURITY_WIN32
 #include <windows.h>
 #include <sspi.h>
-#include <SecExt.h>
+#include <secext.h>
 #include <stdarg.h>
 #include <stdio.h>
 
 #define SSPI_MAX_TOKEN_SIZE 50000
 #define SEC_ERROR(err) (err < 0)
-extern void sspi_errmsg(int err, char *buf, size_t size);
\ No newline at end of file
+extern void sspi_errmsg(int err, char *buf, size_t size);