diff --git a/Makefile b/Makefile
index 45ab20fd..03a26cd7 100644
--- a/Makefile
+++ b/Makefile
@@ -104,6 +104,7 @@ clean:
 	@$(MAKE) -C contrib/pzstd $@ > $(VOID)
 	@$(MAKE) -C contrib/seekable_format/examples $@ > $(VOID)
 	@$(MAKE) -C contrib/adaptive-compression $@ > $(VOID)
+	@$(MAKE) -C contrib/largeNbDicts $@ > $(VOID)
 	@$(RM) zstd$(EXT) zstdmt$(EXT) tmp*
 	@$(RM) -r lz4
 	@echo Cleaning completed
diff --git a/contrib/largeNbDicts/Makefile b/contrib/largeNbDicts/Makefile
index cf529399..0514e3d8 100644
--- a/contrib/largeNbDicts/Makefile
+++ b/contrib/largeNbDicts/Makefile
@@ -15,6 +15,7 @@ LIBZSTD = $(LIBDIR)/libzstd.a
 CPPFLAGS+= -I$(LIBDIR) -I$(LIBDIR)/common -I$(LIBDIR)/dictBuilder -I$(PROGDIR)
 
 CFLAGS  ?= -O3
+CFLAGS  += -std=c99
 DEBUGFLAGS= -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
             -Wstrict-aliasing=1 -Wswitch-enum \
             -Wstrict-prototypes -Wundef -Wpointer-arith -Wformat-security \