diff --git a/.travis.yml b/.travis.yml
index 184169d043fecad44d3d894d9b94916cd4e7c27e..416e26f31035f60931fe22a46c03c38772129628 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,13 +29,13 @@ jobs:
           sudo: required
         - stage: "Build"
           name: "Android 32 bit"
-          dist: trusty
+          dist: xenial
           language: android
           env: SPEC=android-clang CONFIG=installer BITNESS=32 GSTREAMER_NAME=armv7
           sudo: false
         - stage: "Build"
           name: "Android 64 bit"
-          dist: trusty
+          dist: xenial
           language: android
           env: SPEC=android-clang CONFIG=installer BITNESS=64 GSTREAMER_NAME=arm64
           sudo: false
diff --git a/doc/README b/doc/README
index 2d8755731b0f4b5faa5d905af99fecd14d7ee0bf..ea1e6e719e5623c24a7d0c6e07b055edd2b1441c 100644
--- a/doc/README
+++ b/doc/README
@@ -12,3 +12,10 @@ $doxygen Doxyfile
 
 The html file index.html should be in doc/html. 
 
+Debian
+=====================
+#To build documentation first install dependencies (doxygen, doxyqml and dot):
+sudo apt install doxygen graphviz doxyqml
+
+#Then build documentation in the doc/ directory
+doxygen ./Doxyfile
diff --git a/doc/dot b/doc/dot
index 48ed5a4abe0bb4f3b654e12ac344493be34dab8e..07f4f280d5912049140ae63bfd8feb85609afadb 100755
--- a/doc/dot
+++ b/doc/dot
@@ -34,4 +34,13 @@ do
   fi
 done
 
-/usr/local/bin/dot ${ARGS}
+if [[ -x "/usr/local/bin/dot" ]]  
+then
+  /usr/local/bin/dot ${ARGS}
+elif [[ -x "/usr/bin/dot" ]]
+then 
+  /usr/bin/dot ${ARGS}
+else
+  echo "Program dot not found: See file doc/dot"
+  exit 1
+fi