diff --git a/Makefile.in b/Makefile.in
index 9e5aab5f4..34519dc10 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -192,7 +192,7 @@ iverilog-vpi: $(srcdir)/iverilog-vpi.sh Makefile
 endif
 
 version.exe: $(srcdir)/version.c $(srcdir)/version_base.h version_tag.h
-	$(HOSTCC) -o version.exe -I. -I$(srcdir) $(srcdir)/version.c
+	$(HOSTCC) -Wall -o version.exe -I. -I$(srcdir) $(srcdir)/version.c
 
 dep:
 	mkdir dep
diff --git a/vvp/Makefile.in b/vvp/Makefile.in
index c003dc17e..b17380602 100644
--- a/vvp/Makefile.in
+++ b/vvp/Makefile.in
@@ -46,6 +46,7 @@ MAN = @MAN@
 PS2PDF = @PS2PDF@
 
 CPPFLAGS = -I. -I.. -I $(srcdir) -I$(srcdir)/.. @CPPFLAGS@ @DEFS@
+CFLAGS = -Wall @CFLAGS@
 CXXFLAGS = -Wall @CXXFLAGS@
 LDFLAGS = @rdynamic@ @LDFLAGS@
 LIBS = @LIBS@ @EXTRALIBS@
@@ -112,7 +113,7 @@ dep:
 	mv $*.d dep/$*.d
 
 tables.cc: $(srcdir)/draw_tt.c
-	$(HOSTCC) -o draw_tt $(srcdir)/draw_tt.c
+	$(HOSTCC) -Wall -o draw_tt $(srcdir)/draw_tt.c
 	./draw_tt > tables.cc
 	rm draw_tt@EXEEXT@