diff --git a/doc/developers/makefiles b/doc/developers/makefiles
index 4a800247..8d285fdc 100644
--- a/doc/developers/makefiles
+++ b/doc/developers/makefiles
@@ -32,7 +32,7 @@ The best way to understand the Module.mk subfiles is to examine one of them,
 for example lib/Module.mk. They are not too difficult to understand.
 
 There are several variables which can be set in the main Makefile. You can
-also specify them on the command-line; this overrules any definitions 
+also specify them on the command-line; this overrules any definitions
 within the Makefile. For example: 'make all WARN=1' will enable all warnings.
 Examine main Makefile to see which ones are available. The most important
 ones for developers:
@@ -47,15 +47,15 @@ Several files are generated by Makefiles:
     Dependency files for modules. Automatically generated.
   * .rd
     Dependency files for executables. Automatically generated.
-  * .ao
+  * .ad
     Dependency files for static libraries. Automatically generated.
-  * .lo
+  * .ld
     Dependency files for shared libraries. Automatically generated.
   * .o
     Generated modules
   * .ro
     Object files for executables. They will be linked together to create
-    the executable. This extension is used to distinguish them from 
+    the executable. This extension is used to distinguish them from
     modules (which end on .o). Also, using a different extensions makes
     the Makefile fragments much simpler.
   * .ao