diff --git a/closed/OpenJ9.gmk b/closed/OpenJ9.gmk
index 3042116e80..5a7e9a55ee 100644
--- a/closed/OpenJ9.gmk
+++ b/closed/OpenJ9.gmk
@@ -27,7 +27,6 @@ ifeq (,$(wildcard $(SPEC)))
 endif
 include $(SPEC)
 include $(TOPDIR)/make/common/MakeBase.gmk
-include $(TOPDIR)/closed/JPP.gmk
 
 ifeq (,$(BUILD_ID))
   BUILD_ID := 000000
diff --git a/closed/autoconf/custom-spec.gmk.in b/closed/autoconf/custom-spec.gmk.in
index 2ea6623745..bce99fa2c5 100644
--- a/closed/autoconf/custom-spec.gmk.in
+++ b/closed/autoconf/custom-spec.gmk.in
@@ -166,7 +166,6 @@ $(foreach var, \
 	$(eval $(var) += -I$(SUPPORT_OUTPUTDIR)/openj9_include))
 
 J9JCL_SOURCES_DIR      := $(SUPPORT_OUTPUTDIR)/j9jcl
-J9JCL_SOURCES_DONEFILE := $(MAKESUPPORT_OUTPUTDIR)/j9jcl.done
 
 ifeq (riscv64,$(OPENJDK_TARGET_CPU))
   ifeq (cross,$(COMPILE_TYPE))
diff --git a/closed/GensrcJ9JCL.gmk b/closed/custom/Main-post.gmk
similarity index 94%
rename from closed/GensrcJ9JCL.gmk
rename to closed/custom/Main-post.gmk
index 6cc0d3df43..2b20224083 100644
--- a/closed/GensrcJ9JCL.gmk
+++ b/closed/custom/Main-post.gmk
@@ -18,12 +18,6 @@
 # 2 along with this work; if not, see <http://www.gnu.org/licenses/>.
 # ===========================================================================
 
-.PHONY : all
-
-all :
-
-include $(SPEC)
-include $(TOPDIR)/make/common/MakeBase.gmk
 include $(TOPDIR)/closed/JPP.gmk
 
 RecursiveWildcard = $(foreach dir,$(wildcard $1/*),$(call RecursiveWildcard,$(dir),$2) $(filter $(subst *,%,$2),$(dir)))
@@ -59,6 +53,8 @@ $(eval $(call SetupCopyFiles,COPY_OVERLAY_FILES, \
 
 IncludeIfUnsure := -includeIfUnsure -noWarnIncludeIf
 
+J9JCL_SOURCES_DONEFILE := $(MAKESUPPORT_OUTPUTDIR)/j9jcl.done
+
 $(J9JCL_SOURCES_DONEFILE) : \
 		$(foreach dir, $(JppSourceDirs), $(call RecursiveWildcard,$(dir),*)) \
 		$(COPY_OVERLAY_FILES)
@@ -80,4 +76,7 @@ $(J9JCL_SOURCES_DONEFILE) : \
 	@$(MKDIR) -p $(@D)
 	@$(TOUCH) $@
 
-all : $(J9JCL_SOURCES_DONEFILE)
+# Force (re-)generation of module dependencies after preprocessing OpenJ9 source files.
+$(MODULE_DEPS_MAKEFILE) : $(J9JCL_SOURCES_DONEFILE)
+
+# $(error in Main-post.gmk)
diff --git a/closed/custom/Main.gmk b/closed/custom/Main.gmk
index 43131afd24..fcb702dce7 100644
--- a/closed/custom/Main.gmk
+++ b/closed/custom/Main.gmk
@@ -36,14 +36,6 @@ PHASE_MAKEDIRS := $(TOPDIR)/closed/make $(PHASE_MAKEDIRS)
 
 OPENJ9_MAKE := $(MAKE) $(MAKE_ARGS) -f $(TOPDIR)/closed/OpenJ9.gmk
 
-# An early part of the build process involves computing the list of main targets.
-# Those targets include {module}-java, {module}-jmod, etc. which requires that the
-# set of module names be known. We must build and run the preprocessor to ensure the
-# modules specific to OpenJ9 will be found and included in that set. The next two
-# rules make that happen.
-
-create-main-targets-include java.base-gensrc : generate-j9jcl-sources
-
 j9vm-build : buildtools-langtools
   ifeq ($(BUILD_OPENSSL),yes)
 	@+$(MAKE) $(MAKE_ARGS) -f $(TOPDIR)/closed/openssl.gmk
diff --git a/closed/custom/common/Modules.gmk b/closed/custom/common/Modules.gmk
index 445fe5569f..1a10f34246 100644
--- a/closed/custom/common/Modules.gmk
+++ b/closed/custom/common/Modules.gmk
@@ -59,16 +59,3 @@ TOP_SRC_DIRS += \
 ifeq (true,$(BUILD_OPENJCEPLUS))
   TOP_SRC_DIRS += $(OPENJCEPLUS_TOPDIR)/src/main
 endif
-
-.PHONY : generate-j9jcl-sources
-
-generate-j9jcl-sources $(J9JCL_SOURCES_DONEFILE) :
-	@+$(MAKE) $(MAKE_ARGS) -f $(TOPDIR)/closed/GensrcJ9JCL.gmk
-
-# When building multiple configurations at once (e.g. 'make CONF= images')
-# the 'create-main-targets-include' target will only be considered for the
-# first configuration; J9JCL source generation will be delayed for other
-# configurations. In order to produce a complete module-deps.gmk, we need
-# to ensure that the J9JCL source has been generated.
-
--include $(J9JCL_SOURCES_DONEFILE)