diff --git a/Modules/_bytesio.c b/Modules/_bytesio.c
index d7d2667..48fe50a 100644
--- a/Modules/_bytesio.c
+++ b/Modules/_bytesio.c
@@ -221,6 +221,8 @@
 
     if (PyLong_Check(arg)) {
         size = PyLong_AsSsize_t(arg);
+        if (size == -1 && PyErr_Occurred())
+            return NULL;
     }
     else if (arg == Py_None) {
         /* Read until EOF is reached, by default. */
@@ -288,6 +290,8 @@
 
     if (PyLong_Check(arg)) {
         size = PyLong_AsSsize_t(arg);
+        if (size == -1 && PyErr_Occurred())
+            return NULL;
     }
     else if (arg == Py_None) {
         /* No size limit, by default. */
@@ -332,6 +336,8 @@
 
     if (PyLong_Check(arg)) {
         maxsize = PyLong_AsSsize_t(arg);
+        if (maxsize == -1 && PyErr_Occurred())
+            return NULL;
     }
     else if (arg == Py_None) {
         /* No size limit, by default. */
@@ -415,6 +421,8 @@
 
     if (PyLong_Check(arg)) {
         size = PyLong_AsSsize_t(arg);
+        if (size == -1 && PyErr_Occurred())
+            return NULL;
     }
     else if (arg == Py_None) {
         /* Truncate to current position if no argument is passed. */
diff --git a/Modules/_struct.c b/Modules/_struct.c
index 4a257c0..ac70f43 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1786,6 +1786,8 @@
 
 	/* Extract the offset from the first argument */
 	offset = PyLong_AsSsize_t(PyTuple_GET_ITEM(args, 1));
+	if (offset == -1 && PyErr_Occurred())
+		return NULL;
 
 	/* Support negative offsets. */
 	if (offset < 0)