diff --git a/Misc/NEWS b/Misc/NEWS
index aa023884d85..c4f0eeefe62 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -708,6 +708,9 @@ Library
 Extension Modules
 -----------------
 
+- Bug #1649098: Avoid declaration of zero-sized array declaration in
+  structure.
+
 - Removed the rgbimg module; been deprecated since Python 2.5.
 
 - Bug #1721309: prevent bsddb module from freeing random memory.
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index c57dc07be2f..18af288ce26 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -268,7 +268,7 @@ ffi_info *AllocFunctionCallback(PyObject *callable,
 	ffi_abi cc;
 
 	nArgs = PySequence_Size(converters);
-	p = (ffi_info *)PyMem_Malloc(sizeof(ffi_info) + sizeof(ffi_type) * (nArgs + 1));
+	p = (ffi_info *)PyMem_Malloc(sizeof(ffi_info) + sizeof(ffi_type) * (nArgs));
 	if (p == NULL) {
 		PyErr_NoMemory();
 		return NULL;
diff --git a/Modules/_ctypes/ctypes.h b/Modules/_ctypes/ctypes.h
index 5846e3fc594..bf2bdaa6ffc 100644
--- a/Modules/_ctypes/ctypes.h
+++ b/Modules/_ctypes/ctypes.h
@@ -75,7 +75,7 @@ typedef struct {
 	PyObject *callable;
 	SETFUNC setfunc;
 	ffi_type *restype;
-	ffi_type *atypes[0];
+	ffi_type *atypes[1];
 } ffi_info;
 
 typedef struct {