diff --git a/.travis.yml b/.travis.yml
index 94c9357..076ea49 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,31 +3,27 @@ branches:
     - master
     - ci # CI testing
 
-language: cpp
 
-cache:
-  apt: true
+language: generic  # Avoid system resetting CC/CXX before install
 
+dist: xenial
 addons:
   apt:
     sources:
       - ubuntu-toolchain-r-test
     packages:
-      - g++-8
-  env: COMPILER=gcc-8 COMPILERXX=g++-8
+      - g++-8 # Install newer libstdc++ also required by clang
 
 matrix:
   include:
-    - compiler: gcc
-      env: COMPILER=gcc-8 COMPILERXX=g++-8
+    - compiler: gcc-8
+      env: CC=gcc-8 CXX=g++-8
 
-install:
-  # Overwrite compiler variables
-  - if [[ "${COMPILER}" != "" ]]; then
-      export CC=${COMPILER};
-      export CXX=${COMPILERXX};
-    fi
+    - compiler: clang
+      env: CC=clang CXX=clang++
 
 script:
+  # DMC
   - cd dmc && mkdir build && cd build && cmake .. && make -j3
+  # DME
   #- cd dme && mkdir build && cd build && cmake .. && make -j3
diff --git a/dmc/src/Scanner.h b/dmc/src/Scanner.h
index e769f56..74f45dc 100644
--- a/dmc/src/Scanner.h
+++ b/dmc/src/Scanner.h
@@ -68,16 +68,16 @@ class Scanner {
             automata[0][i] = automata[1][i] = automata[2][i] = 1;
         }
         // In state 1, next is dot, go to state 2
-        automata[1]['.'] = 2;
+        automata[1][(uint8_t)'.'] = 2;
 
         /* Operator */
         // In state 0, next is '+', '*', '-', '/', '^' or '%', go to state 3
-        automata[0]['+'] = automata[0]['*'] = automata[0]['-'] =
-        automata[0]['/'] = automata[0]['^'] = automata[0]['%'] = 3;
+        automata[0][(uint8_t)'+'] = automata[0][(uint8_t)'*'] = automata[0][(uint8_t)'-'] =
+        automata[0][(uint8_t)'/'] = automata[0][(uint8_t)'^'] = automata[0][(uint8_t)'%'] = 3;
 
         /* Separator */
         // In state 0, next is '(', ')' or ';', go to state 4
-        automata[0]['('] = automata[0][')'] = automata[0][';'] = 4;
+        automata[0][(uint8_t)'('] = automata[0][(uint8_t)')'] = automata[0][(uint8_t)';'] = 4;
 
         /* Identifier */
         // In state 0 or 6, next is alphanumeric, go to state 6
@@ -91,14 +91,14 @@ class Scanner {
         for (int i = '0'; i <= '9'; i++) {
             automata[6][i] = 6;
         }
-        automata[6]['-'] = automata[6]['_'] = automata[6][':'] = 6;
+        automata[6][(uint8_t)'-'] = automata[6][(uint8_t)'_'] = automata[6][(uint8_t)':'] = 6;
 
         /* Ignore */
         // In state 0 or 5, next is white-space, go to state 5
-        automata[0]['\n'] = automata[5]['\n'] =
-        automata[0][' ']  = automata[5][' ']  =
-        automata[0]['\t'] = automata[5]['\t'] =
-        automata[0]['\r'] = automata[5]['\r'] = 5;
+        automata[0][(uint8_t)'\n'] = automata[5][(uint8_t)'\n'] =
+        automata[0][(uint8_t)' ']  = automata[5][(uint8_t)' ']  =
+        automata[0][(uint8_t)'\t'] = automata[5][(uint8_t)'\t'] =
+        automata[0][(uint8_t)'\r'] = automata[5][(uint8_t)'\r'] = 5;
 
         // State 0 not finite, returns lexical error
         finite[0] = Token::LexError;