diff --git a/Makefile.target b/Makefile.target
index 69535dfa26..bd5cafe06b 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -73,7 +73,7 @@ PROGS=$(QEMU_PROG)
 
 # We require -O2 to avoid the stack setup prologue in EXIT_TB
 OP_CFLAGS := -O2 -g -fno-strict-aliasing
-OP_CFLAGS += -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes
+OP_CFLAGS += -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes
 
 # cc-option
 # Usage: OP_CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)
diff --git a/configure b/configure
index f7d41f49cf..72f5cd5f52 100755
--- a/configure
+++ b/configure
@@ -381,7 +381,7 @@ done
 
 # default flags for all hosts
 CFLAGS="$CFLAGS -O2 -g -fno-strict-aliasing"
-CFLAGS="$CFLAGS -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes"
+CFLAGS="$CFLAGS -Wall -Wundef -Wendif-labels -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes"
 LDFLAGS="$LDFLAGS -g"
 if test "$werror" = "yes" ; then
 CFLAGS="$CFLAGS -Werror"