diff --git a/.travis.yml b/.travis.yml
index 60737725c..ef12c8f32 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,6 +17,10 @@ compiler: gcc
 # deprecated
 #sudo: required
 
+# turns off submodule fetching by default
+git:
+  submodules: false
+
 env:
   global:
     - FC=gfortran
diff --git a/README.md b/README.md
index e8993214e..a2bb5542c 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,11 @@ involved in the community and keep them in the specfem3d github wiki:
 [specfem3d wiki](https://github.com/SPECFEM/specfem3d/wiki)
 
 
+## Our contributors :sparkles:
+
+[![SPECFEM3D contributors](https://contrib.rocks/image?repo=SPECFEM/specfem3d)](https://github.com/SPECFEM/specfem3d/graphs/contributors)
+
+
 ## Computational Infrastructure for Geodynamics (CIG)
 
 SPECFEM3D is part of the software that is hosted by the Computational Infrastructure for Geodynamics (CIG). It is available on the CIG website [here (SPECFEM3D)](https://geodynamics.org/resources/specfem3dcartesian).
diff --git a/doc/USER_MANUAL/authors.tex b/doc/USER_MANUAL/authors.tex
index c392c5414..15688a3a2 100644
--- a/doc/USER_MANUAL/authors.tex
+++ b/doc/USER_MANUAL/authors.tex
@@ -73,6 +73,7 @@ \section*{Authors}
 Elliott Sales de Andrade,
 Brian Savage,
 Bernhard Schuberth,
+Eyal Shimony,
 Anne Sieminski,
 James Smith,
 Leif Strand,
diff --git a/m4 b/m4
index e490e14fb..f5b39ccf9 160000
--- a/m4
+++ b/m4
@@ -1 +1 @@
-Subproject commit e490e14fb13595428d39055304bcf0ee7ab94806
+Subproject commit f5b39ccf9ebf30a919f1a36ea05a3b53e84cd899