diff --git a/Makefile.inc1 b/Makefile.inc1
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -1830,6 +1830,11 @@
 installkernel installkernel.debug \
 reinstallkernel reinstallkernel.debug: _installcheck_kernel .PHONY
 .if !defined(NO_INSTALLKERNEL)
+.if defined(PACKAGE_BUILDING)
+_kernel=${INSTALLKERNEL}.${INSTKERNNAME}
+.else
+_kernel=${INSTKERNNAME}
+.endif
 .if empty(INSTALLKERNEL)
 	@echo "ERROR: No kernel \"${KERNCONF}\" to install."; \
 	false
@@ -1839,9 +1844,9 @@
 	@echo "--------------------------------------------------------------"
 	${_+_}cd ${KRNLOBJDIR}/${INSTALLKERNEL}; \
 	    ${CROSSENV} PATH=${TMPPATH:Q} \
-	    ${MAKE} ${IMAKE_INSTALL} KERNEL=${INSTKERNNAME} ${.TARGET:S/kernel//}
+	    ${MAKE} ${IMAKE_INSTALL} KERNEL=${_kernel} ${.TARGET:S/kernel//}
 	@echo "--------------------------------------------------------------"
-	@echo ">>> Installing kernel ${INSTALLKERNEL} completed on $$(LC_ALL=C date)"
+	@echo ">>> Installing kernel ${_kernel} completed on $$(LC_ALL=C date)"
 	@echo "--------------------------------------------------------------"
 .endif
 .if ${BUILDKERNELS:[#]} > 1 && ${NO_INSTALLEXTRAKERNELS} != "yes"