--- configure.orig	2017-12-05 15:02:11 UTC
+++ configure
@@ -25273,13 +25273,15 @@ case $AFS_SYSNAME in
 		;;
 
 	i386_fbsd_*)
+		KERN_OPTMZ=
+		LWP_OPTMZ=
 		MT_CFLAGS='-DAFS_PTHREAD_ENV -pthread -D_REENTRANT ${XCFLAGS}'
-		MT_LIBS="-pthread"
-		PAM_OPTMZ=-O2
-		PAM_CFLAGS="-pipe -fPIC"
+		MT_LIBS="${_MT_LIBS:--pthread}"
+		PAM_OPTMZ=
+		PAM_CFLAGS="${_PAM_CFLAGS:--pipe -fPIC}"
 		SHLIB_LDFLAGS="-shared -Xlinker -x"
 		SHLIB_LINKER="${MT_CC} -shared"
-		XCFLAGS="-pipe"
+		XCFLAGS="${_XCFLAGS:--pipe}"
 		;;
 
 	i386_dfbsd_*)
@@ -25293,12 +25295,15 @@ case $AFS_SYSNAME in
 		;;
 
 	amd64_fbsd_*)
+		KERN_OPTMZ=
+		LWP_OPTMZ=
 		MT_CFLAGS='-DAFS_PTHREAD_ENV -pthread -D_REENTRANT ${XCFLAGS}'
-		MT_LIBS="-pthread"
-		PAM_CFLAGS="-O2 -pipe -fPIC"
+		MT_LIBS="${_MT_LIBS:--pthread}"
+		PAM_OPTMZ=
+		PAM_CFLAGS="${_PAM_CFLAGS:--O2 -pipe -fPIC}"
 		SHLIB_LDFLAGS="-shared -Xlinker -x"
 		SHLIB_LINKER="${MT_CC} -shared"
-		XCFLAGS="-O2 -pipe -fPIC"
+		XCFLAGS="${_XCFLAGS:--O2 -pipe -fPIC}"
 		;;
 
 	*nbsd2*|*nbsd3*|*nbsd4*|*nbsd5*|*nbsd6*)