diff --git a/src/system/boot/platform/openfirmware/arch/ppc/Jamfile b/src/system/boot/platform/openfirmware/arch/ppc/Jamfile
index f7c3d95efc..14a364fb08 100644
--- a/src/system/boot/platform/openfirmware/arch/ppc/Jamfile
+++ b/src/system/boot/platform/openfirmware/arch/ppc/Jamfile
@@ -8,14 +8,20 @@ UsePrivateHeaders kernel [ FDirName kernel arch $(TARGET_KERNEL_ARCH) ]
 
 SubDirC++Flags -fno-rtti ;
 
-BootStaticLibrary boot_platform_openfirmware_ppc.o :
-	arch_mmu.cpp
-	arch_cpu_asm.S
-	arch_start_kernel.S
-	cpu.cpp
-	mmu.cpp
-	start.cpp
-;
+local platform ;
+for platform in [ MultiBootSubDirSetup openfirmware ] {
+	on $(platform) {
+
+		BootMergeObject boot_platform_openfirmware_ppc.o :
+			arch_mmu.cpp
+			arch_cpu_asm.S
+			arch_start_kernel.S
+			cpu.cpp
+			mmu.cpp
+			start.cpp
+		;
+		SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
+    		= [ FDirName $(HAIKU_TOP) src system kernel arch $(TARGET_KERNEL_ARCH) ] ;
+	}
+}
 
-SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
-    = [ FDirName $(HAIKU_TOP) src system kernel arch $(TARGET_KERNEL_ARCH) ] ;
diff --git a/src/system/boot/platform/openfirmware/arch/sparc/Jamfile b/src/system/boot/platform/openfirmware/arch/sparc/Jamfile
index 1990ac2577..371b56060a 100644
--- a/src/system/boot/platform/openfirmware/arch/sparc/Jamfile
+++ b/src/system/boot/platform/openfirmware/arch/sparc/Jamfile
@@ -8,12 +8,18 @@ UsePrivateHeaders kernel [ FDirName kernel arch $(TARGET_KERNEL_ARCH) ]
 
 SubDirC++Flags -fno-rtti ;
 
-BootMergeObject boot_platform_openfirmware_sparc.o :
-	arch_start_kernel.S
-	cpu.cpp
-	mmu.cpp
-	start.cpp
-;
+local platform ;
+for platform in [ MultiBootSubDirSetup openfirmware ] {
+	on $(platform) {
 
-SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
-    = [ FDirName $(HAIKU_TOP) src system kernel arch $(TARGET_KERNEL_ARCH) ] ;
+		BootMergeObject boot_platform_openfirmware_sparc.o :
+			arch_start_kernel.S
+			cpu.cpp
+			mmu.cpp
+			start.cpp
+		;
+
+		SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
+		    = [ FDirName $(HAIKU_TOP) src system kernel arch $(TARGET_KERNEL_ARCH) ] ;
+	}
+}