diff --git a/sys/conf/kern.pre.mk b/sys/conf/kern.pre.mk
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@@ -252,8 +252,7 @@
 # Special flags for managing the compat compiles for ZFS
 ZFS_CFLAGS+=	-I$S/contrib/openzfs/module/icp/include \
 	${CDDL_CFLAGS} -DBUILDING_ZFS -DHAVE_UIO_ZEROCOPY \
-	-DWITH_NETDUMP -D__KERNEL__ -D_SYS_CONDVAR_H_ -DSMP \
-	-DIN_FREEBSD_BASE
+	-DWITH_NETDUMP -D__KERNEL__ -D_SYS_CONDVAR_H_ -DSMP
 
 .if ${MACHINE_ARCH} == "amd64"
 ZFS_CFLAGS+= -D__x86_64 -DHAVE_SSE2 -DHAVE_SSSE3 -DHAVE_SSE4_1 -DHAVE_SSE4_2 \
diff --git a/sys/contrib/openzfs/include/sys/spa.h b/sys/contrib/openzfs/include/sys/spa.h
--- a/sys/contrib/openzfs/include/sys/spa.h
+++ b/sys/contrib/openzfs/include/sys/spa.h
@@ -723,16 +723,10 @@
  * Send TRIM commands in-line during normal pool operation while deleting.
  *	OFF: no
  *	ON: yes
- * NB: IN_FREEBSD_BASE is defined within the FreeBSD sources.
  */
 typedef enum {
 	SPA_AUTOTRIM_OFF = 0,	/* default */
 	SPA_AUTOTRIM_ON,
-#ifdef IN_FREEBSD_BASE
-	SPA_AUTOTRIM_DEFAULT = SPA_AUTOTRIM_ON,
-#else
-	SPA_AUTOTRIM_DEFAULT = SPA_AUTOTRIM_OFF,
-#endif
 } spa_autotrim_t;
 
 /*
diff --git a/sys/contrib/openzfs/module/zcommon/zpool_prop.c b/sys/contrib/openzfs/module/zcommon/zpool_prop.c
--- a/sys/contrib/openzfs/module/zcommon/zpool_prop.c
+++ b/sys/contrib/openzfs/module/zcommon/zpool_prop.c
@@ -160,7 +160,7 @@
 	    "wait | continue | panic", "FAILMODE", failuremode_table,
 	    sfeatures);
 	zprop_register_index(ZPOOL_PROP_AUTOTRIM, "autotrim",
-	    SPA_AUTOTRIM_DEFAULT, PROP_DEFAULT, ZFS_TYPE_POOL,
+	    SPA_AUTOTRIM_OFF, PROP_DEFAULT, ZFS_TYPE_POOL,
 	    "on | off", "AUTOTRIM", boolean_table, sfeatures);
 
 	/* hidden properties */
diff --git a/sys/modules/zfs/Makefile b/sys/modules/zfs/Makefile
--- a/sys/modules/zfs/Makefile
+++ b/sys/modules/zfs/Makefile
@@ -38,7 +38,7 @@
 
 CFLAGS+= -D__KERNEL__ -DFREEBSD_NAMECACHE -DBUILDING_ZFS \
 	-DHAVE_UIO_ZEROCOPY -DWITHOUT_NETDUMP -D__KERNEL -D_SYS_CONDVAR_H_ \
-	-D_SYS_VMEM_H_ -DIN_FREEBSD_BASE
+	-D_SYS_VMEM_H_
 
 .if ${MACHINE_ARCH} == "amd64"
 CFLAGS+= -D__x86_64 -DHAVE_SSE2 -DHAVE_SSSE3 -DHAVE_SSE4_1 -DHAVE_SSE4_2 \