diff --git a/Doc/library/_thread.rst b/Doc/library/_thread.rst
index e7e7504c420..751c3e8849c 100644
--- a/Doc/library/_thread.rst
+++ b/Doc/library/_thread.rst
@@ -94,7 +94,7 @@ It defines the following constants and functions:
    *size* argument specifies the stack size to be used for subsequently created
    threads, and must be 0 (use platform or configured default) or a positive
    integer value of at least 32,768 (32kB). If changing the thread stack size is
-   unsupported, a :exc:`ThreadError` is raised.  If the specified stack size is
+   unsupported, a :exc:`RuntimeError` is raised.  If the specified stack size is
    invalid, a :exc:`ValueError` is raised and the stack size is unmodified.  32kB
    is currently the minimum supported stack size value to guarantee sufficient
    stack space for the interpreter itself.  Note that some platforms may have
diff --git a/Doc/library/threading.rst b/Doc/library/threading.rst
index 2b43ee5e70d..7527bc5e862 100644
--- a/Doc/library/threading.rst
+++ b/Doc/library/threading.rst
@@ -174,7 +174,7 @@ This module defines the following functions and objects:
    *size* argument specifies the stack size to be used for subsequently created
    threads, and must be 0 (use platform or configured default) or a positive
    integer value of at least 32,768 (32kB). If changing the thread stack size is
-   unsupported, a :exc:`ThreadError` is raised.  If the specified stack size is
+   unsupported, a :exc:`RuntimeError` is raised.  If the specified stack size is
    invalid, a :exc:`ValueError` is raised and the stack size is unmodified.  32kB
    is currently the minimum supported stack size value to guarantee sufficient
    stack space for the interpreter itself.  Note that some platforms may have