diff --git a/doc/Installation/Installation-(Debian-Ubuntu).md b/doc/Installation/Installation-(Debian-Ubuntu).md
index e7a56447c..45dd02778 100644
--- a/doc/Installation/Installation-(Debian-Ubuntu).md
+++ b/doc/Installation/Installation-(Debian-Ubuntu).md
@@ -134,6 +134,8 @@ Change the values to the right of the equal sign for lines beginning with `$conf
 
 Change the value of `$config['snmp']['community']` from `public` to whatever your read-only SNMP community is.  If you have multiple communities, set it to the most common.
 
+** Be sure you have no characters (including whitespace like: newlines, spaces, tabs, etc) outside of the `<?php>` blocks. Your graphs will break otherwise. **
+
 ### Initialise the database ###
 
 Initiate the follow database with the following command:
diff --git a/doc/Installation/Installation-(RHEL-CentOS).md b/doc/Installation/Installation-(RHEL-CentOS).md
index e7b3d4998..9d9575089 100644
--- a/doc/Installation/Installation-(RHEL-CentOS).md
+++ b/doc/Installation/Installation-(RHEL-CentOS).md
@@ -143,6 +143,8 @@ Add the following line to the end of `config.php`:
 
     $config['fping'] = "/usr/sbin/fping";
 
+** Be sure you have no characters (including whitespace like: newlines, spaces, tabs, etc) outside of the `<?php>` blocks. Your graphs will break otherwise. **
+
 ### Initialise the database ###
 
 Initiate the follow database with the following command:
diff --git a/doc/Installation/Installation-Lighttpd-(Debian-Ubuntu).md b/doc/Installation/Installation-Lighttpd-(Debian-Ubuntu).md
index 3d95a539a..c844878dd 100644
--- a/doc/Installation/Installation-Lighttpd-(Debian-Ubuntu).md
+++ b/doc/Installation/Installation-Lighttpd-(Debian-Ubuntu).md
@@ -58,6 +58,8 @@ Change the values to the right of the equal sign for lines beginning with `$conf
 
 Change the value of `$config['snmp']['community']` from `public` to whatever your read-only SNMP community is.  If you have multiple communities, set it to the most common.
 
+** Be sure you have no characters (including whitespace like: newlines, spaces, tabs, etc) outside of the `<?php>` blocks. Your graphs will break otherwise. **
+
 ### Initialise the database ###
 
 Initiate the follow database with the following command: