diff --git a/src/doc/man/cargo-doc.md b/src/doc/man/cargo-doc.md
index c97f13a0b83..5d87c72e640 100644
--- a/src/doc/man/cargo-doc.md
+++ b/src/doc/man/cargo-doc.md
@@ -32,7 +32,7 @@ Do not build documentation for dependencies.
 {{/option}}
 
 {{#option "`--document-private-items`" }}
-Include non-public items in the documentation.
+Include non-public items in the documentation. This will be enabled by default if documenting a binary target.
 {{/option}}
 
 {{/options}}
diff --git a/src/doc/man/generated_txt/cargo-doc.txt b/src/doc/man/generated_txt/cargo-doc.txt
index b81160f4406..a7b160b54b1 100644
--- a/src/doc/man/generated_txt/cargo-doc.txt
+++ b/src/doc/man/generated_txt/cargo-doc.txt
@@ -23,7 +23,8 @@ OPTIONS
            Do not build documentation for dependencies.
 
        --document-private-items
-           Include non-public items in the documentation.
+           Include non-public items in the documentation. This will be enabled
+           by default if documenting a binary target.
 
    Package Selection
        By default, when no package selection options are given, the packages
diff --git a/src/etc/man/cargo-doc.1 b/src/etc/man/cargo-doc.1
index cb700b2f870..46bb4dca3bd 100644
--- a/src/etc/man/cargo-doc.1
+++ b/src/etc/man/cargo-doc.1
@@ -28,7 +28,7 @@ Do not build documentation for dependencies.
 .sp
 \fB\-\-document\-private\-items\fR
 .RS 4
-Include non\-public items in the documentation.
+Include non\-public items in the documentation. This will be enabled by default if documenting a binary target.
 .RE
 .SS "Package Selection"
 By default, when no package selection options are given, the packages selected