diff --git a/Makefile.inc1 b/Makefile.inc1
index 8bf192d5590f..ba7fe523774b 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -1001,7 +1001,7 @@ buildkernel:
 	cd ${KRNLCONFDIR}; \
 		PATH=${TMPPATH} \
 		    config ${CONFIGARGS} -d ${KRNLOBJDIR}/${_kernel} \
-			-I ${KERNCONFDIR} ${KERNCONFDIR}/${_kernel}
+			-I '${KERNCONFDIR}' '${KERNCONFDIR}/${_kernel}'
 .endif
 .if !defined(NO_CLEAN) && !defined(NO_KERNELCLEAN)
 	@echo
@@ -1816,7 +1816,7 @@ DTBOUTPUTPATH= ${KRNLOBJDIR}/${KERNCONF}/
 .if !defined(FDT_DTS_FILE) || empty(FDT_DTS_FILE)
 .if exists(${KERNCONFDIR}/${KERNCONF})
 FDT_DTS_FILE!= awk 'BEGIN {FS="="} /^makeoptions[[:space:]]+FDT_DTS_FILE/ {print $$2}' \
-	${KERNCONFDIR}/${KERNCONF} ; echo
+	'${KERNCONFDIR}/${KERNCONF}' ; echo
 .endif
 .endif
 
diff --git a/tools/tools/nanobsd/nanobsd.sh b/tools/tools/nanobsd/nanobsd.sh
index 3f7fbe29ab58..274132c27430 100644
--- a/tools/tools/nanobsd/nanobsd.sh
+++ b/tools/tools/nanobsd/nanobsd.sh
@@ -233,7 +233,7 @@ build_kernel ( ) (
 
 	(
 	if [ -f ${NANO_KERNEL} ] ; then
-		extra="KERNCONFDIR=$(realpath $(dirname ${NANO_KERNEL}))"
+		kernconfdir_arg="KERNCONFDIR='$(realpath $(dirname ${NANO_KERNEL}))'"
 		kernconf=$(basename ${NANO_KERNEL})
 	else
 		kernconf=${NANO_KERNEL}
@@ -245,10 +245,10 @@ build_kernel ( ) (
 	unset TARGET_CPUTYPE
 	# Note: We intentionally build all modules, not only the ones in
 	# NANO_MODULES so the built world can be reused by multiple images.
-	env TARGET_ARCH=${NANO_ARCH} ${NANO_PMAKE} buildkernel \
-		SRCCONF=${SRCCONF} \
-		${extra} __MAKE_CONF=${NANO_MAKE_CONF_BUILD} \
-		KERNCONF=${kernconf}
+	eval "TARGET_ARCH=${NANO_ARCH} ${NANO_PMAKE} buildkernel \
+		SRCCONF='${SRCCONF}' \
+		__MAKE_CONF='${NANO_MAKE_CONF_BUILD}' \
+		${kernconfdir_arg} KERNCONF=${kernconf}"
 	) > ${MAKEOBJDIRPREFIX}/_.bk 2>&1
 )
 
@@ -315,19 +315,19 @@ install_kernel ( ) (
 
 	(
 	if [ -f ${NANO_KERNEL} ] ; then
-		extra="KERNCONFDIR=$(realpath $(dirname ${NANO_KERNEL}))"
+		kernconfdir_arg="KERNCONFDIR='$(realpath $(dirname ${NANO_KERNEL}))'"
 		kernconf=$(basename ${NANO_KERNEL})
 	else
 		kernconf=${NANO_KERNEL}
 	fi
 
 	cd ${NANO_SRC}
-	env TARGET_ARCH=${NANO_ARCH} ${NANO_MAKE} installkernel \
-		DESTDIR=${NANO_WORLDDIR} \
-		SRCCONF=${SRCCONF} \
-		${extra} __MAKE_CONF=${NANO_MAKE_CONF_INSTALL} \
-		KERNCONF=${kernconf} \
-		MODULES_OVERRIDE="${NANO_MODULES}"
+	eval "TARGET_ARCH=${NANO_ARCH} ${NANO_MAKE} installkernel \
+		DESTDIR='${NANO_WORLDDIR}' \
+		SRCCONF='${SRCCONF}' \
+		__MAKE_CONF='${NANO_MAKE_CONF_INSTALL}' \
+		${kernconfdir_arg} KERNCONF=${kernconf} \
+		MODULES_OVERRIDE='${NANO_MODULES}'"
 	) > ${NANO_OBJ}/_.ik 2>&1
 )