diff --git a/.travis.yml b/.travis.yml
index 7a54f23..f3512f7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,10 @@ matrix:
       os: linux
       compiler: gcc
       sudo: false
+    - env: TASK="gcc6"   # gcc-6
+      os: linux
+      compiler: gcc-6
+      sudo: false
     - env: TASK="arm-linux-gnueabihf-gcc" # arm build
       os: linux
       compiler: gcc
@@ -57,6 +61,10 @@ addons:
     - mingw32-runtime
     - wine
     - xvfb
+    - gcc-6
+    - g++-6
+    sources:
+    - sourceline: 'ppa:ubuntu-toolchain-r/test'
   coverity_scan:
     project:
       name: "MycroftAI/mimic"
diff --git a/run_testsuite.sh b/run_testsuite.sh
index 311cefe..c9d157c 100755
--- a/run_testsuite.sh
+++ b/run_testsuite.sh
@@ -152,6 +152,18 @@ case "${WHAT_TO_RUN}" in
     # for ubuntu precise in travis, that does not provide pkg-config:
     pkg-config --exists icui18n || export CFLAGS="$CFLAGS -I/usr/include/x86_64-linux-gnu"
     pkg-config --exists icui18n || export LDFLAGS="$LDFLAGS -licui18n -licuuc -licudata"
+    export CFLAGS="$CFLAGS --std=c99"
+    ./configure  --enable-shared || exit 1
+    make || exit 1
+    make check || exit 1
+    ;;
+  gcc6)
+    ./autogen.sh
+    # for ubuntu precise in travis, that does not provide pkg-config:
+    pkg-config --exists icui18n || export CFLAGS="$CFLAGS -I/usr/include/x86_64-linux-gnu"
+    pkg-config --exists icui18n || export LDFLAGS="$LDFLAGS -licui18n -licuuc -licudata"
+    export CC="/usr/bin/gcc-6"
+    export CXX="/usr/bin/g++-6"
     ./configure  --enable-shared || exit 1
     make || exit 1
     make check || exit 1
diff --git a/src/audio/au_alsa.c b/src/audio/au_alsa.c
index 9048e23..33770cf 100644
--- a/src/audio/au_alsa.c
+++ b/src/audio/au_alsa.c
@@ -43,7 +43,7 @@
 
 #ifdef CST_AUDIO_ALSA
 
-#define _BSD_SOURCE /* alsa alloca stuff and nanosleep */
+#define _POSIX_C_SOURCE 200112L
 
 #include <stdlib.h>
 #include <unistd.h>
@@ -56,6 +56,9 @@
 #include "cst_wave.h"
 #include "cst_audio.h"
 
+/* alloca.h is not C99 compliant nor POSIX compliant, but alsa needs it and does not include it */
+/* See similar patch: https://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2008-July/058080.html */
+#include <alloca.h>
 #include <alsa/asoundlib.h>
 
 int audio_flush_alsa(cst_audiodev *ad);
diff --git a/src/utils/cst_mmap_posix.c b/src/utils/cst_mmap_posix.c
index 990072a..ac85f23 100644
--- a/src/utils/cst_mmap_posix.c
+++ b/src/utils/cst_mmap_posix.c
@@ -40,7 +40,7 @@
 
 #if (MMAP_TYPE == MMAP_TYPE_POSIX)
 
-# define _POSIX_C_SOURCE 200809L
+# define _POSIX_C_SOURCE 200112L
 
 #include <sys/types.h>
 #include <sys/mman.h>
diff --git a/src/utils/cst_socket.c b/src/utils/cst_socket.c
index f171c41..1aa3310 100644
--- a/src/utils/cst_socket.c
+++ b/src/utils/cst_socket.c
@@ -62,6 +62,7 @@ int cst_socket_close(int socket)
     return -1;
 }
 #else
+#define _POSIX_C_SOURCE 200112L
 #include <stdio.h>
 #include <stdlib.h>
 #ifndef _MSC_VER
@@ -81,6 +82,11 @@ int cst_socket_close(int socket)
 #include "cst_socket.h"
 #include "cst_error.h"
 
+/* OSX el capitan does not define INADDR_NONE in all cases */
+#ifndef INADDR_NONE
+#define INADDR_NONE ((in_addr_t) -1)
+#endif
+
 int cst_socket_open(const char *host, int port)
 {
     /* Return an FD to a remote server */
@@ -105,7 +111,7 @@ int cst_socket_open(const char *host, int port)
             cst_errmsg("cst_socket: gethostbyname failed\n");
             return -1;
         }
-        memmove(&serv_addr.sin_addr, serverhost->h_addr,
+        memmove(&serv_addr.sin_addr, serverhost->h_addr_list[0],
                 serverhost->h_length);
     }
     serv_addr.sin_family = AF_INET;
diff --git a/src/utils/cst_url.c b/src/utils/cst_url.c
index 7437d28..d36c6a9 100644
--- a/src/utils/cst_url.c
+++ b/src/utils/cst_url.c
@@ -41,6 +41,9 @@
 /*  Only support http: if sockets are available                          */
 /*                                                                       */
 /*************************************************************************/
+
+#define _POSIX_C_SOURCE 200112L
+
 #include <math.h>
 #include "cst_file.h"
 #include "cst_string.h"
diff --git a/unittests/cutest.h b/unittests/cutest.h
index 64b5784..9031fa8 100644
--- a/unittests/cutest.h
+++ b/unittests/cutest.h
@@ -87,13 +87,12 @@
  **********************/
 
 /* The unit test files should not rely on anything below. */
-
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-#if defined(unix) || defined(__unix__) || defined(__unix) || defined(__APPLE__)
+#if (defined(unix) || defined(__unix__) || defined(__unix) || defined(__APPLE__)) && !defined(__STRICT_ANSI__)
     #define CUTEST_UNIX__    1
     #include <errno.h>
     #include <unistd.h>
@@ -102,12 +101,16 @@
     #include <signal.h>
 #endif
 
-#if defined(_WIN32) || defined(__WIN32__) || defined(__WINDOWS__)
+#if (defined(_WIN32) || defined(__WIN32__) || defined(__WINDOWS__)) && !defined(__STRICT_ANSI__)
     #define CUTEST_WIN__     1
     #include <windows.h>
     #include <io.h>
 #endif
 
+#if defined(__STRICT_ANSI__)
+    #define CUTEST_ANSI__    1
+#endif
+
 #ifdef __cplusplus
     #include <exception>
 #endif
@@ -162,16 +165,16 @@ test_print_in_color__(int color, const char* fmt, ...)
     {
         const char* col_str;
         switch(color) {
-            case CUTEST_COLOR_GREEN__:             col_str = "\e[0;32m"; break;
-            case CUTEST_COLOR_RED__:               col_str = "\e[0;31m"; break;
-            case CUTEST_COLOR_GREEN_INTENSIVE__:   col_str = "\e[1;32m"; break;
-            case CUTEST_COLOR_RED_INTENSIVE__:     col_str = "\e[1;30m"; break;
-            case CUTEST_COLOR_DEFAULT_INTENSIVE__: col_str = "\e[1m"; break;
-            default:                               col_str = "\e[0m"; break;
+            case CUTEST_COLOR_GREEN__:             col_str = "\033[0;32m"; break;
+            case CUTEST_COLOR_RED__:               col_str = "\033[0;31m"; break;
+            case CUTEST_COLOR_GREEN_INTENSIVE__:   col_str = "\033[1;32m"; break;
+            case CUTEST_COLOR_RED_INTENSIVE__:     col_str = "\033[1;30m"; break;
+            case CUTEST_COLOR_DEFAULT_INTENSIVE__: col_str = "\033[1m"; break;
+            default:                               col_str = "\033[0m"; break;
         }
         printf("%s", col_str);
         n = printf("%s", buffer);
-        printf("\e[0m");
+        printf("\033[0m");
         return n;
     }
 #elif defined CUTEST_WIN__
@@ -352,9 +355,10 @@ test_do_run__(const struct test__* test)
     return (test_current_failures__ == 0) ? 0 : -1;
 }
 
+#if !defined(CUTEST_ANSI__)
 /* Called if anything goes bad in cutest, or if the unit test ends in other
  * way then by normal returning from its function (e.g. exception or some
- * abnormal child process termination). */
+ * abnormal child process termination). On CUTEST_ANSI__ this is not used so we don't define it*/
 static void
 test_error__(const char* fmt, ...)
 {
@@ -377,6 +381,7 @@ test_error__(const char* fmt, ...)
         printf("\n");
     }
 }
+#endif
 
 /* Trigger the unit test. If possible (and not suppressed) it starts a child
  * process who calls test_do_run__(), otherwise it calls test_do_run__()
@@ -458,7 +463,7 @@ test_run__(const struct test__* test)
             failed = 1;
         }
 
-#else
+#else /* CUTEST_ANSI__ */
 
         /* A platform where we don't know how to run child process. */
         failed = (test_do_run__(test) != 0);
@@ -650,4 +655,3 @@ main(int argc, char** argv)
 
 
 #endif  /* #ifndef CUTEST_H__ */
-