diff -Naur postfix-3.7.2.org/makedefs postfix-3.7.2/makedefs
--- postfix-3.7.2.org/makedefs	2022-01-23 21:53:41.000000000 +0100
+++ postfix-3.7.2/makedefs	2022-10-18 16:11:50.259575443 +0200
@@ -627,7 +627,7 @@
 		: ${SHLIB_ENV="LD_LIBRARY_PATH=`pwd`/lib"}
 		: ${PLUGIN_LD="${CC-gcc} -shared"}
 		;;
- Linux.[345].*)	SYSTYPE=LINUX$RELEASE_MAJOR
+ Linux.[3-6].*)	SYSTYPE=LINUX$RELEASE_MAJOR
 		case "$CCARGS" in
 		 *-DNO_DB*) ;;
 		 *-DHAS_DB*) ;;
diff -Naur postfix-3.7.2.org/src/util/sys_defs.h postfix-3.7.2/src/util/sys_defs.h
--- postfix-3.7.2.org/src/util/sys_defs.h	2021-12-05 19:59:27.000000000 +0100
+++ postfix-3.7.2/src/util/sys_defs.h	2022-10-18 16:09:29.682371415 +0200
@@ -751,7 +751,7 @@
  /*
   * LINUX.
   */
-#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5)
+#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5) || defined(LINUX6)
 #define SUPPORTED
 #define UINT32_TYPE	unsigned int
 #define UINT16_TYPE	unsigned short
