diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8daabc5..41fe9b8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,24 @@ project(
   VERSION ${VERSION}
   LANGUAGES C)
 
+if(NOT CMAKE_BUILD_TYPE)
+  set(CMAKE_BUILD_TYPE Release)
+endif()
+
+include(CheckTypeSize)
+check_type_size("long long" HAVE_LONG_LONG)
+include(CheckFunctionExists)
+check_function_exists(snprintf HAVE_SNPRINTF)
+check_function_exists(vasprintf HAVE_VASPRINTF)
+check_function_exists(vsnprintf HAVE_VSNPRINTF)
+check_function_exists(strdup HAVE_STRDUP)
+check_function_exists(strlcat HAVE_STRLCAT)
+check_function_exists(strlcpy HAVE_STRLCPY)
+set(MXML_VERSION "Mini-XML v${VERSION}")
+
+configure_file(cmake/config.h.in config.h)
+set(HEADERS mxml-private.h ${CMAKE_CURRENT_BINARY_DIR}/config.h)
+
 set(SOURCES
     mxml-attr.c
     mxml-entity.c
@@ -19,9 +37,6 @@ set(SOURCES
     mxml-set.c
     mxml-string.c)
 
-#configure_file(config.h.in config.h)
-set(HEADERS mxml-private.h cmake/config.h)
-
 add_library(${PROJECT_NAME} ${SOURCES} ${HEADERS})
 target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
 add_library(MSweet::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
diff --git a/cmake/config.h b/cmake/config.h.in
similarity index 77%
rename from cmake/config.h
rename to cmake/config.h.in
index ebcc302..e81b88c 100644
--- a/cmake/config.h
+++ b/cmake/config.h.in
@@ -24,7 +24,7 @@
  * Version number...
  */
 
-#define MXML_VERSION "Mini-XML v3.2"
+#cmakedefine MXML_VERSION "@MXML_VERSION@"
 
 
 /*
@@ -38,25 +38,25 @@
  * Long long support...
  */
 
-#define HAVE_LONG_LONG 1
+#cmakedefine HAVE_LONG_LONG 1
 
 
 /*
  * Do we have the *printf() functions?
  */
 
-#define HAVE_SNPRINTF 1
-#define HAVE_VASPRINTF 1
-#define HAVE_VSNPRINTF 1
+#cmakedefine HAVE_SNPRINTF 1
+#cmakedefine HAVE_VASPRINTF 1
+#cmakedefine HAVE_VSNPRINTF 1
 
 
 /*
  * Do we have the strXXX() functions?
  */
 
-#define HAVE_STRDUP 1
-#define HAVE_STRLCAT 1
-#define HAVE_STRLCPY 1
+#cmakedefine HAVE_STRDUP 1
+#cmakedefine HAVE_STRLCAT 1
+#cmakedefine HAVE_STRLCPY 1
 
 
 /*