--- a/extras/gudev/docs/Makefile.am
+++ b/extras/gudev/docs/Makefile.am
@@ -21,7 +21,7 @@ DOC_MAIN_SGML_FILE=$(DOC_MODULE)-docs.xm
 # gtk-doc will search all .c & .h files beneath here for inline comments
 # documenting the functions and macros.
 # e.g. DOC_SOURCE_DIR=../../../gtk
-DOC_SOURCE_DIR=..
+DOC_SOURCE_DIR=$(abs_srcdir)
 
 # Extra options to pass to gtkdoc-scangobj. Not normally needed.
 SCANGOBJ_OPTIONS=
--- a/libudev/docs/Makefile.am
+++ b/libudev/docs/Makefile.am
@@ -21,7 +21,7 @@ DOC_MAIN_SGML_FILE=$(DOC_MODULE)-docs.xm
 # gtk-doc will search all .c & .h files beneath here for inline comments
 # documenting the functions and macros.
 # e.g. DOC_SOURCE_DIR=../../../gtk
-DOC_SOURCE_DIR=..
+DOC_SOURCE_DIR=$(abs_srcdir)
 
 # Extra options to pass to gtkdoc-scangobj. Not normally needed.
 SCANGOBJ_OPTIONS=
