diff --git a/bundler/man/bundle-config.1 b/bundler/man/bundle-config.1
index 1c5b54e77f88..762b18f2e0f0 100644
--- a/bundler/man/bundle-config.1
+++ b/bundler/man/bundle-config.1
@@ -154,7 +154,7 @@ The following is a list of all configuration keys and their purpose\. You can le
 \fBbin\fR (\fBBUNDLE_BIN\fR): Install executables from gems in the bundle to the specified directory\. Defaults to \fBfalse\fR\.
 .
 .IP "\(bu" 4
-\fBcache_all\fR (\fBBUNDLE_CACHE_ALL\fR): Cache all gems, including path and git gems\.
+\fBcache_all\fR (\fBBUNDLE_CACHE_ALL\fR): Cache all gems, including path and git gems\. This needs to be explicitly configured on bundler 1 and bundler 2, but will be the default on bundler 3\.
 .
 .IP "\(bu" 4
 \fBcache_all_platforms\fR (\fBBUNDLE_CACHE_ALL_PLATFORMS\fR): Cache gems for all platforms\.
diff --git a/bundler/man/bundle-config.1.ronn b/bundler/man/bundle-config.1.ronn
index 9b8eb94c1b4e..a0ff30cb1559 100644
--- a/bundler/man/bundle-config.1.ronn
+++ b/bundler/man/bundle-config.1.ronn
@@ -150,7 +150,8 @@ learn more about their operation in [bundle install(1)](bundle-install.1.html).
    Install executables from gems in the bundle to the specified directory.
    Defaults to `false`.
 * `cache_all` (`BUNDLE_CACHE_ALL`):
-   Cache all gems, including path and git gems.
+   Cache all gems, including path and git gems. This needs to be explicitly
+   configured on bundler 1 and bundler 2, but will be the default on bundler 3.
 * `cache_all_platforms` (`BUNDLE_CACHE_ALL_PLATFORMS`):
    Cache gems for all platforms.
 * `cache_path` (`BUNDLE_CACHE_PATH`):