diff --git a/Modules/_ctypes/libffi/src/x86/ffi.c b/Modules/_ctypes/libffi/src/x86/ffi.c
index 7f792b7..cc63b6b 100644
--- a/Modules/_ctypes/libffi/src/x86/ffi.c
+++ b/Modules/_ctypes/libffi/src/x86/ffi.c
@@ -174,7 +174,7 @@
 			  /*@out@*/ extended_cif *, 
 			  unsigned, unsigned, 
 			  /*@out@*/ unsigned *, 
-			  void (*fn)());
+			  void (*fn)(void));
 /*@=declundef@*/
 /*@=exportheader@*/
 
@@ -185,13 +185,13 @@
 			  /*@out@*/ extended_cif *,
 			  unsigned, unsigned,
 			  /*@out@*/ unsigned *,
-			  void (*fn)());
+			  void (*fn)(void));
 /*@=declundef@*/
 /*@=exportheader@*/
 #endif /* X86_WIN32 */
 
 void ffi_call(/*@dependent@*/ ffi_cif *cif, 
-	      void (*fn)(), 
+	      void (*fn)(void), 
 	      /*@out@*/ void *rvalue, 
 	      /*@dependent@*/ void **avalue)
 {
@@ -405,7 +405,7 @@
 	      /*@out@*/ extended_cif *, 
 	      unsigned, unsigned, 
 	      /*@out@*/ unsigned *, 
-	      void (*fn)());
+	      void (*fn)(void));
 
 #ifdef X86_WIN32
 extern void
@@ -413,12 +413,12 @@
 	      /*@out@*/ extended_cif *,
 	      unsigned, unsigned,
 	      /*@out@*/ unsigned *,
-	      void (*fn)());
+	      void (*fn)(void));
 #endif /* X86_WIN32 */
 
 void
 ffi_raw_call(/*@dependent@*/ ffi_cif *cif, 
-	     void (*fn)(), 
+	     void (*fn)(void), 
 	     /*@out@*/ void *rvalue, 
 	     /*@dependent@*/ ffi_raw *fake_avalue)
 {
diff --git a/Modules/_ctypes/libffi/src/x86/ffi64.c b/Modules/_ctypes/libffi/src/x86/ffi64.c
index c6cf330..fa352f7 100644
--- a/Modules/_ctypes/libffi/src/x86/ffi64.c
+++ b/Modules/_ctypes/libffi/src/x86/ffi64.c
@@ -42,7 +42,7 @@
 };
 
 extern void ffi_call_unix64 (void *args, unsigned long bytes, unsigned flags,
-			     void *raddr, void (*fnaddr)(), unsigned ssecount);
+			     void *raddr, void (*fnaddr)(void), unsigned ssecount);
 
 /* All reference to register classes here is identical to the code in
    gcc/config/i386/i386.c. Do *not* change one without the other.  */
@@ -339,7 +339,7 @@
 }
 
 void
-ffi_call (ffi_cif *cif, void (*fn)(), void *rvalue, void **avalue)
+ffi_call (ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue)
 {
   enum x86_64_reg_class classes[MAX_CLASSES];
   char *stack, *argp;