diff --git a/third_party/minizip/ioapi.h b/third_party/minizip/ioapi.h
index c588a18d..effadc09 100644
--- a/third_party/minizip/ioapi.h
+++ b/third_party/minizip/ioapi.h
@@ -18,6 +18,12 @@
 
 */
 
+
+/* Pragma added by libxlsxwriter to avoid warnings with -pedantic -ansi. */
+#ifndef _WIN32
+#pragma GCC system_header
+#endif
+
 #ifndef _ZLIBIOAPI64_H
 #define _ZLIBIOAPI64_H
 
diff --git a/third_party/minizip/zip.h b/third_party/minizip/zip.h
index 5fc08413..3837bbae 100644
--- a/third_party/minizip/zip.h
+++ b/third_party/minizip/zip.h
@@ -37,6 +37,11 @@
 
 */
 
+/* Pragma added by libxlsxwriter to avoid warnings with -pedantic -ansi. */
+#ifndef _WIN32
+#pragma GCC system_header
+#endif
+
 #ifndef _zip12_H
 #define _zip12_H
 
@@ -54,6 +59,14 @@ extern "C" {
 #include "ioapi.h"
 #endif
 
+/* Encryption not required by libxlsxwriter. */
+#ifndef NOCRYPT
+#define NOCRYPT
+#endif
+#ifndef NOUNCRYPT
+#define NOUNCRYPT
+#endif
+
 #ifdef HAVE_BZIP2
 #include "bzlib.h"
 #endif