diff --git a/make/cache.mk b/make/cache.mk
index 0c049057..a1372d97 100644
--- a/make/cache.mk
+++ b/make/cache.mk
@@ -6,6 +6,8 @@
 CACHE_PROJECT_MK            ?= .cache-project.mk
 CACHED_VARS_ONLY_PROJECT    ?= \
 	PROJECT \
+	PREREQ_BUILD \
+	PREREQ_RUN \
 	PREREQ \
 	VERSION \
 	HEX_VERSION \
diff --git a/make/defs.mk b/make/defs.mk
index f8beacec..0533ae55 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -503,6 +503,18 @@ endif
 INSTALL_FILE                ?= $(INSTALL)
 INSTALL_DIR                 ?= $(INSTALL)
 
+ifeq ($(origin PREREQ_BUILD),undefined)
+  PREREQ_BUILD              := $(call proj_query, pkg-requires --no-subpackages --subsections=jw --syntax names-only --delimiter ' ' 'build devel' $(PROJECT))
+endif
+
+ifeq ($(origin PREREQ_RUN),undefined)
+  PREREQ_RUN                := $(call proj_query, pkg-requires --no-subpackages --subsections=jw --syntax names-only --delimiter ' ' 'run' $(PROJECT))
+endif
+
+ifeq ($(origin PREREQ),undefined)
+  PREREQ                    := $(sort $(PREREQ_BUILD) $(PREREQ_RUN))
+endif
+
 # ----- local.mk
 
 $(eval $(call try_include,$(JWBDIR)/make/local.mk))
diff --git a/make/make.mk b/make/make.mk
index 373858b7..d71e0a23 100644
--- a/make/make.mk
+++ b/make/make.mk
@@ -9,8 +9,8 @@ include $(JWBDIR)/make/defs-dirs.mk
 include $(JWBDIR)/make/dev-utils.mk
 
 CACHED_FILES                ?= $(VERSION_FILE) $(wildcard $(TOPDIR)/make/project.conf)
-CACHED_VARS                 ?= PROJECT PREREQ VERSION HEX_VERSION FULL_NAME \
-				WHICH PYTHON ECHO TEST BROWSER SED RM PWD ID CUT TR \
+CACHED_VARS                 ?= PROJECT PREREQ_BUILD PREREQ_RUN PREREQ VERSION HEX_VERSION \
+				FULL_NAME WHICH PYTHON ECHO TEST BROWSER SED RM PWD ID CUT TR \
 				AWK GETENT XARGS FIND PRINTF PLATFORM_INFO OS_NAME_VERSION \
 				CAT BIN_INSTALL SUDO \
 				JW_PKG_LD_LIBRARY_PATH JW_PKG_EXE_PATH JW_PKG_PYTHON_PATH
diff --git a/make/topdir.mk b/make/topdir.mk
index b8957248..a4a4dd7f 100644
--- a/make/topdir.mk
+++ b/make/topdir.mk
@@ -80,23 +80,18 @@ REMOTE_GIT_DIR               = /$(JANWARE_USER)/$(REMOTE_GIT_FLAVOUR)/$(PROJECT)
 REMOTE_GIT_URL               = ssh://$(JANWARE_USER_PREFIX)devgit.janware.com$(REMOTE_GIT_DIR)
 
 ifneq ($(DONT_CHECK_PREREQ_DONE),true)
-  ifndef PREREQ
-    PREREQ                  := $(call proj_query,pkg-requires --no-subpackages --subsections=jw  --syntax names-only --delimiter=' ' build $(PROJECT))
+  ifndef PREREQ_DIRS_BUILD
+    PREREQ_DIRS_BUILD       := $(call proj_query,proj-dir $(PREREQ_BUILD))
   endif
-  ifndef PREREQ_DIRS
-    PREREQ_DIRS             := $(call proj_query,proj-dir $(PREREQ))
-  endif
-  PREREQ_DIRS_DONE          := $(addsuffix /dirs-all.done,$(filter-out $(TOPDIR) /opt/%,$(PREREQ_DIRS)))
+  PREREQ_DIRS_BUILD_DONE    := $(addsuffix /dirs-all.done,$(filter-out $(TOPDIR) /opt/%,$(PREREQ_DIRS_BUILD)))
 endif
 
 ifneq ($(SUBDIRS_TO_ITERATE),)
-
   ifeq ($(MAKECMDGOALS),)
     SUBDIR_TARGETS           = all
   else
     SUBDIR_TARGETS           = $(filter $(ALLOWED_SUBDIR_TARGETS),$(MAKECMDGOALS))
   endif
-
 endif
 
 all: topdir config