diff --git a/config.h.cmake b/config.h.cmake
index 06c18da66c8..c48d17fada0 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -643,4 +643,12 @@
 #cmakedefine SIZEOF_TIME_T @SIZEOF_TIME_T@
 #cmakedefine TIME_T_UNSIGNED @TIME_T_UNSIGNED@
 
+#ifdef _AIX
+/*
+  AIX includes inttypes.h from sys/types.h
+  Explicitly request format macros before the first inclusion of inttypes.h
+*/
+#define __STDC_FORMAT_MACROS
+#endif
+
 #endif