example: Fix building with optimization flags.
diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
index d03c40a..12d1397 100644
--- a/example/CMakeLists.txt
+++ b/example/CMakeLists.txt
@@ -1,4 +1,4 @@
-project(cmocka-examples C CXX)
+project(cmocka-examples C)
 
 include_directories(
     ${CMAKE_BINARY_DIR}
@@ -6,7 +6,14 @@
     ${CMOCKA_PUBLIC_INCLUDE_DIRS}
 )
 
-add_definitions(-DUNIT_TESTING=1)
+set_source_files_properties(
+    calculator.c
+    calculator_test.c
+    allocate_module.c
+    allocate_module_test.c
+    run_tests.c
+    PROPERTIES
+        COMPILE_FLAGS -DUNIT_TESTING=1)
 
 add_executable(calculator_test calculator.c calculator_test.c)
 target_link_libraries(calculator_test ${CMOCKA_SHARED_LIBRARY})
@@ -68,11 +75,11 @@
         "\\[  FAILED  \\] 2 test"
 )
 
-if (${CMAKE_C_COMPILER_ID} MATCHES "(GNU|Clang)")
-    add_subdirectory(chef_wrap)
-endif()
-
 add_executable(run_tests run_tests.c)
 target_link_libraries(run_tests ${CMOCKA_SHARED_LIBRARY})
 
 add_test(run_tests ${CMAKE_CURRENT_BINARY_DIR}/run_tests)
+
+if (${CMAKE_C_COMPILER_ID} MATCHES "(GNU|Clang)")
+    add_subdirectory(chef_wrap)
+endif()
diff --git a/example/chef_wrap/CMakeLists.txt b/example/chef_wrap/CMakeLists.txt
index b6bd6b5..60d5a36 100644
--- a/example/chef_wrap/CMakeLists.txt
+++ b/example/chef_wrap/CMakeLists.txt
@@ -1,4 +1,4 @@
-project(cmocka-wrap-examples C CXX)
+project(cmocka-wrap-examples C)
 
 include_directories(
     ${CMAKE_BINARY_DIR}
@@ -6,8 +6,6 @@
     ${CMOCKA_PUBLIC_INCLUDE_DIRS}
 )
 
-add_definitions(-DUNIT_TESTING=1)
-
 add_executable(waiter_test_wrap waiter_test_wrap.c chef.c)
 target_link_libraries(waiter_test_wrap ${CMOCKA_SHARED_LIBRARY})
 
diff --git a/example/chef_wrap/waiter_test_wrap.c b/example/chef_wrap/waiter_test_wrap.c
index a981967..f65d5de 100644
--- a/example/chef_wrap/waiter_test_wrap.c
+++ b/example/chef_wrap/waiter_test_wrap.c
@@ -15,14 +15,15 @@
  * limitations under the License.
  */
 
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
 #include <stdarg.h>
 #include <stddef.h>
 #include <setjmp.h>
 #include <cmocka.h>
-#include <stdio.h>
-#include <errno.h>
-#include <stdbool.h>
-#include <string.h>
 
 #include "waiter_test_wrap.h"
 #include "chef.h"