Index: .travis.yml
===================================================================
diff -u -N -r9808a2f313759926b7881c8c0c283d13bcf55371 -r6259567bacd6f4ea2ca2c63260a7e9d520e24afc
--- .travis.yml	(.../.travis.yml)	(revision 9808a2f313759926b7881c8c0c283d13bcf55371)
+++ .travis.yml	(.../.travis.yml)	(revision 6259567bacd6f4ea2ca2c63260a7e9d520e24afc)
@@ -29,12 +29,12 @@
             - g++-7
       env: TCLTAG=core-8-branch
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-branch
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env: TCLTAG=core-8-branch
      # ----------------------------
     - os: linux
@@ -52,12 +52,12 @@
             - g++-7
       env: TCLTAG=core-8-7-a3
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-7-a3
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env: TCLTAG=core-8-7-a3
     # ----------------------------
     - os: linux
@@ -75,12 +75,12 @@
             - g++-7
       env: TCLTAG=core-8-5-19
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-5-19
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env:
        -  TCLTAG=core-8-5-19
    # ----------------------------
@@ -99,12 +99,12 @@
             - g++-7
       env: TCLTAG=core-8-5-branch
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-5-branch
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env:
         - TCLTAG=core-8-5-branch
   # ----------------------------
@@ -123,12 +123,12 @@
             - g++-7
       env: TCLTAG=core-8-6-10
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-6-10
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env:
         - TCLTAG=core-8-6-10
   # ----------------------------
@@ -147,12 +147,12 @@
             - g++-7
       env: TCLTAG=core-8-6-branch
     - os: osx
-      osx_image: xcode10.2
+      osx_image: xcode11.3
       compiler: clang
       env: TCLTAG=core-8-6-branch
     - os: osx
-      osx_image: xcode10.2	
-      compiler: gcc-8
+      osx_image: xcode11.3	
+      compiler: gcc-9
       env: TCLTAG=core-8-6-branch
   allow_failures:
   - env: TCLTAG=core-8-6-branch