diff --git a/Makefile b/Makefile
index ef378102..40f7bcd1 100644
--- a/Makefile
+++ b/Makefile
@@ -49,12 +49,12 @@ build_library_type/%: generate_sources
 	@${RM} src/gnatcoll-atomic.adb
 
 	@echo "====== Building $(@F) libraries ======"
-	${GPRBUILD} ${GPRBLD_OPTS} -Pgnatcoll_full
+	${GPRBUILD} ${GPRBLD_OPTS} -Pgnatcoll_full $(CARGS) $(LARGS)
 
 	@# Need to build libgnatcoll_gtk separately, because its project files
 	@# requires gtkada.gpr, which might not exist on the machine.
 ifeq (${WITH_GTK},yes)
-	${GPRBUILD} ${GPRBLD_OPTS} -Psrc/gnatcoll_gtk
+	${GPRBUILD} ${GPRBLD_OPTS} -Psrc/gnatcoll_gtk $(CARGS) $(LARGS)
 endif
 
 build_tools/%: build_library_type/%
@@ -63,7 +63,7 @@ build_tools/%: build_library_type/%
 	@# They are not build as part of the above because only the Main from
 	@# gnatcoll_full.gpr are build. We could use aggregate projects to
 	@# speed things up.
-	${GPRBUILD} ${GPRBLD_OPTS} -q -Psrc/gnatcoll_tools
+	${GPRBUILD} ${GPRBLD_OPTS} -q -Psrc/gnatcoll_tools $(CARGS) $(LARGS)
 
 #######################################################################
 #  install
@@ -126,10 +126,10 @@ SQLITE_DIR=src/sqlite/amalgamation
 sqlite3_shell: $(SQLITE_DIR)/sqlite3_for_gps
 $(SQLITE_DIR)/sqlite3_for_gps: $(SQLITE_DIR)/shell.c $(SQLITE_DIR)/sqlite3.c
 ifeq ($(OS),Windows_NT)
-	-cd $(SQLITE_DIR); gcc -O2 -DSQLITE_OMIT_LOAD_EXTENSION -D__EXTENSIONS__ -o sqlite3_for_gps shell.c sqlite3.c
+	-cd $(SQLITE_DIR); gcc $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) -DSQLITE_OMIT_LOAD_EXTENSION -D__EXTENSIONS__ -o sqlite3_for_gps shell.c sqlite3.c
 else
 	# If we fail to compile, never mind. Some tests will simply be disabled
-	-cd $(SQLITE_DIR); gcc -O2 -DSQLITE_OMIT_LOAD_EXTENSION -D__EXTENSIONS__ -o sqlite3_for_gps shell.c sqlite3.c -lpthread -ldl
+	-cd $(SQLITE_DIR); gcc $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) -DSQLITE_OMIT_LOAD_EXTENSION -D__EXTENSIONS__ -o sqlite3_for_gps shell.c sqlite3.c -lpthread -ldl
 endif
 
 ## Only works after installation, so we should install to a local directory
diff --git a/Makefile.conf.in b/Makefile.conf.in
index 32975d66..f55ec0f1 100644
--- a/Makefile.conf.in
+++ b/Makefile.conf.in
@@ -91,3 +91,11 @@ DIRSEP=;
 else
 DIRSEP=:
 endif
+
+ifneq ($(strip $(CFLAGS)),)
+CARGS := -cargs $(CFLAGS)
+endif
+
+ifneq ($(strip $(LDFLAGS)),)
+LARGS := -largs $(LDFLAGS)
+endif