diff --git a/.travis.yml b/.travis.yml
index e4ad2f9..6d2ae79 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,7 @@ php:
 
 env:
   global:
-    - ARMA_VERSION="9.700.2"
+    - ARMA_VERSION="9.700.3"
     - ARMA_SRC="http://sourceforge.net/projects/arma/files/armadillo-${ARMA_VERSION}.tar.xz"
 
 before_install:
diff --git a/config.m4 b/config.m4
index 8f000c2..510e248 100644
--- a/config.m4
+++ b/config.m4
@@ -32,7 +32,7 @@ if test "$PHP_ARMA" != "no"; then
 
   # Include PCH file if valid.
   EXTRA_CXXFLAGS="-std=c++17 -DARMA_DONT_PRINT_ERRORS"
-  CLANG_TEST_STR=`$CXX --version | grep clang`
+  CLANG_TEST_STR=`echo | $CXX -dM -E - | grep __clang__`
   if test -f "$PCH_FILE"; then
     if test -n "$CLANG_TEST_STR"; then
       EXTRA_CXXFLAGS+=" -include-pch $PCH_FILE"
diff --git a/src/base.hh b/src/base.hh
index ab4ab61..90b214f 100644
--- a/src/base.hh
+++ b/src/base.hh
@@ -10,6 +10,8 @@
 #include "php_arma.hh"
 #include "complex.hh"
 
+#ifdef PHP_ARMA_OPERATORS
+
 #define PHP_ARMA_BASE_OPERATOR_EX2(cls, type, func)                         \
     PHP_ARMA_OPERATOR_EX2((base<type, cls<type>>), cls<type>, func)
 
@@ -38,6 +40,8 @@
         PHP_ARMA_BASE_ASSIGN_OPERATOR_EX(subview_mat, func)                 \
     PHP_ARMA_OPERATOR_END()
 
+#endif // PHP_ARMA_OPERATORS
+
 namespace php_arma
 {
     template <typename T, typename ChildT>
diff --git a/src/dense.hh b/src/dense.hh
index f847a44..2afe848 100644
--- a/src/dense.hh
+++ b/src/dense.hh
@@ -10,6 +10,8 @@
 #include "php_arma.hh"
 #include "complex.hh"
 
+#ifdef PHP_ARMA_OPERATORS
+
 #define PHP_ARMA_DENSE_OPERATOR_EX2(cls, type, func)                 \
     PHP_ARMA_OPERATOR_EX2((dense<type, cls<type>>), cls<type>, func)
 
@@ -24,6 +26,8 @@
         PHP_ARMA_DENSE_OPERATOR_EX(subview_mat, func)                \
     PHP_ARMA_OPERATOR_END()
 
+#endif // PHP_ARMA_OPERATORS
+
 namespace php_arma
 {
     template <typename T, typename ChildT>
diff --git a/src/mapval.hh b/src/mapval.hh
index 43923ae..0c792af 100644
--- a/src/mapval.hh
+++ b/src/mapval.hh
@@ -9,6 +9,8 @@
 
 #include "php_arma.hh"
 
+#ifdef PHP_ARMA_OPERATORS
+
 #define PHP_ARMA_MAPVAL_OPERATOR_EX(type, func)                 \
     PHP_ARMA_OPERATOR_EX(mapval_dense     <type>, func)         \
     PHP_ARMA_OPERATOR_EX(mapval_spmat     <type>, func)         \
@@ -21,6 +23,8 @@
         PHP_ARMA_MAPVAL_OPERATOR_EX(cx_double, func)            \
     PHP_ARMA_OPERATOR_END()
 
+#endif // PHP_ARMA_OPERATORS
+
 namespace php_arma
 {
     template <typename T, bool IsSparse, bool IsSubview>