diff --git a/lib/cmock_header_parser.rb b/lib/cmock_header_parser.rb
index 7c45a11..4ea9966 100644
--- a/lib/cmock_header_parser.rb
+++ b/lib/cmock_header_parser.rb
@@ -19,6 +19,7 @@ class CMockHeaderParser
     @local_as_void = @treat_as_void
     @verbosity = cfg.verbosity
     @treat_externs = cfg.treat_externs
+    @c_strippables += ['extern'] if (@treat_externs == :include) #we'll need to remove the attribute if we're allowing externs
   end
   
   def parse(name, source)
diff --git a/test/system/test_interactions/all_plugins_coexist.yml b/test/system/test_interactions/all_plugins_coexist.yml
index 1e1e785..b76859f 100644
--- a/test/system/test_interactions/all_plugins_coexist.yml
+++ b/test/system/test_interactions/all_plugins_coexist.yml
@@ -8,6 +8,7 @@
   - :callback
   :callback_after_arg_check: true
   #:callback_include_count: false
+  :treat_externs: :include
 
 :systest:
   :types: |
@@ -18,7 +19,7 @@
 
   :mockable: |
     #include  "CException.h"
-    void foo(POINT_T* a);
+    extern void foo(POINT_T* a);
     POINT_T* bar(void);
     void fooa(POINT_T a[]);
     void foos(const char * a);