diff --git a/Makefile.inc1 b/Makefile.inc1
index bb25d8cab97b..ed325b4431b3 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -1146,7 +1146,7 @@ distributekernel distributekernel.debug:
 	sed -e 's|^./kernel|.|' ${DESTDIR}/${DISTDIR}/kernel.premeta > \
 	    ${DESTDIR}/${DISTDIR}/kernel.meta
 .endif
-.for _kernel in ${BUILDKERNELS:S/${INSTALLKERNEL}//}
+.for _kernel in ${BUILDKERNELS:[2..-1]}
 .if defined(NO_ROOT)
 	echo "#${MTREE_MAGIC}" > ${DESTDIR}/${DISTDIR}/kernel.${_kernel}.premeta
 .endif
@@ -1168,7 +1168,7 @@ packagekernel:
 	cd ${DESTDIR}/${DISTDIR}/kernel; \
 	    tar cvf - @${DESTDIR}/${DISTDIR}/kernel.meta | \
 	    ${XZ_CMD} > ${DESTDIR}/${DISTDIR}/kernel.txz
-.for _kernel in ${BUILDKERNELS:S/${INSTALLKERNEL}//}
+.for _kernel in ${BUILDKERNELS:[2..-1]}
 	cd ${DESTDIR}/${DISTDIR}/kernel.${_kernel}; \
 	    tar cvf - @${DESTDIR}/${DISTDIR}/kernel.${_kernel}.meta | \
 	    ${XZ_CMD} > ${DESTDIR}/${DISTDIR}/kernel.${_kernel}.txz
@@ -1177,7 +1177,7 @@ packagekernel:
 	cd ${DESTDIR}/${DISTDIR}/kernel; \
 	    tar cvf - . | \
 	    ${XZ_CMD} > ${DESTDIR}/${DISTDIR}/kernel.txz
-.for _kernel in ${BUILDKERNELS:S/${INSTALLKERNEL}//}
+.for _kernel in ${BUILDKERNELS:[2..-1]}
 	cd ${DESTDIR}/${DISTDIR}/kernel.${_kernel}; \
 	    tar cvf - . | \
 	    ${XZ_CMD} > ${DESTDIR}/${DISTDIR}/kernel.${_kernel}.txz