diff --git a/include/os/linux/spl/sys/isa_defs.h b/include/os/linux/spl/sys/isa_defs.h
index ee3b74607..5801ec92b 100644
--- a/include/os/linux/spl/sys/isa_defs.h
+++ b/include/os/linux/spl/sys/isa_defs.h
@@ -47,9 +47,6 @@
 #endif
 #endif
 
-#define	_ALIGNMENT_REQUIRED	1
-
-
 /* i386 arch specific defines */
 #elif defined(__i386) || defined(__i386__)
 
@@ -65,8 +62,6 @@
 #define	_ILP32
 #endif
 
-#define	_ALIGNMENT_REQUIRED	0
-
 /* powerpc (ppc64) arch specific defines */
 #elif defined(__powerpc) || defined(__powerpc__) || defined(__powerpc64__)
 
@@ -88,12 +83,6 @@
 #endif
 #endif
 
-/*
- * Illumos doesn't define _ALIGNMENT_REQUIRED for PPC, so default to 1
- * out of paranoia.
- */
-#define	_ALIGNMENT_REQUIRED	1
-
 /* arm arch specific defines */
 #elif defined(__arm) || defined(__arm__)
 
@@ -115,12 +104,6 @@
 #define	_ZFS_BIG_ENDIAN
 #endif
 
-/*
- * Illumos doesn't define _ALIGNMENT_REQUIRED for ARM, so default to 1
- * out of paranoia.
- */
-#define	_ALIGNMENT_REQUIRED	1
-
 /* aarch64 arch specific defines */
 #elif defined(__aarch64__)
 
@@ -157,7 +140,6 @@
 
 #define	_ZFS_BIG_ENDIAN
 #define	_SUNOS_VTOC_16
-#define	_ALIGNMENT_REQUIRED	1
 
 /* s390 arch specific defines */
 #elif defined(__s390__)
@@ -173,12 +155,6 @@
 
 #define	_ZFS_BIG_ENDIAN
 
-/*
- * Illumos doesn't define _ALIGNMENT_REQUIRED for s390, so default to 1
- * out of paranoia.
- */
-#define	_ALIGNMENT_REQUIRED	1
-
 /* MIPS arch specific defines */
 #elif defined(__mips__)
 
@@ -196,12 +172,6 @@
 
 #define	_SUNOS_VTOC_16
 
-/*
- * Illumos doesn't define _ALIGNMENT_REQUIRED for MIPS, so default to 1
- * out of paranoia.
- */
-#define	_ALIGNMENT_REQUIRED	1
-
 /*
  * RISC-V arch specific defines
  * only RV64G (including atomic) LP64 is supported yet
@@ -225,8 +195,6 @@
 
 #define	_SUNOS_VTOC_16
 
-#define	_ALIGNMENT_REQUIRED	1
-
 #else
 /*
  * Currently supported: