diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 738ed2f79dc..0c35f383861 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -539,8 +539,10 @@ static int ConvParam(PyObject *obj, int index, struct argument *pa)
 		size += 1; /* terminating NUL */
 		size *= sizeof(wchar_t);
 		pa->value.p = PyMem_Malloc(size);
-		if (!pa->value.p)
+		if (!pa->value.p) {
+			PyErr_NoMemory();
 			return -1;
+		}
 		memset(pa->value.p, 0, size);
 		pa->keep = PyCObject_FromVoidPtr(pa->value.p, PyMem_Free);
 		if (!pa->keep) {
diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
index c16a387464f..6aa68a8f1ff 100644
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -1389,7 +1389,7 @@ Z_set(void *ptr, PyObject *value, unsigned size)
 		size *= sizeof(wchar_t);
 		buffer = (wchar_t *)PyMem_Malloc(size);
 		if (!buffer)
-			return NULL;
+			return PyErr_NoMemory();
 		memset(buffer, 0, size);
 		keep = PyCObject_FromVoidPtr(buffer, PyMem_Free);
 		if (!keep) {
diff --git a/Modules/_ctypes/stgdict.c b/Modules/_ctypes/stgdict.c
index 8fd9a1e5763..5651d6260a5 100644
--- a/Modules/_ctypes/stgdict.c
+++ b/Modules/_ctypes/stgdict.c
@@ -72,8 +72,10 @@ StgDict_clone(StgDictObject *dst, StgDictObject *src)
 		return 0;
 	size = sizeof(ffi_type *) * (src->length + 1);
 	dst->ffi_type_pointer.elements = PyMem_Malloc(size);
-	if (dst->ffi_type_pointer.elements == NULL)
+	if (dst->ffi_type_pointer.elements == NULL) {
+		PyErr_NoMemory();
 		return -1;
+	}
 	memcpy(dst->ffi_type_pointer.elements,
 	       src->ffi_type_pointer.elements,
 	       size);
@@ -359,6 +361,10 @@ StructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct)
 		total_align = align ? align : 1;
 		stgdict->ffi_type_pointer.type = FFI_TYPE_STRUCT;
 		stgdict->ffi_type_pointer.elements = PyMem_Malloc(sizeof(ffi_type *) * (basedict->length + len + 1));
+		if (stgdict->ffi_type_pointer.elements == NULL) {
+			PyErr_NoMemory();
+			return -1;
+		}
 		memset(stgdict->ffi_type_pointer.elements, 0,
 		       sizeof(ffi_type *) * (basedict->length + len + 1));
 		memcpy(stgdict->ffi_type_pointer.elements,
@@ -373,6 +379,10 @@ StructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct)
 		total_align = 1;
 		stgdict->ffi_type_pointer.type = FFI_TYPE_STRUCT;
 		stgdict->ffi_type_pointer.elements = PyMem_Malloc(sizeof(ffi_type *) * (len + 1));
+		if (stgdict->ffi_type_pointer.elements == NULL) {
+			PyErr_NoMemory();
+			return -1;
+		}
 		memset(stgdict->ffi_type_pointer.elements, 0,
 		       sizeof(ffi_type *) * (len + 1));
 		ffi_ofs = 0;