diff --git a/Makefile b/Makefile
index 8d45ef451..55493f210 100644
--- a/Makefile
+++ b/Makefile
@@ -5,8 +5,37 @@ ifndef HAVE_RULES
     HAVE_RULES=no
 endif
 
+ifndef COMSPEC
+    ifdef ComSpec
+        #### ComSpec is defined on some WIN32's.
+        COMSPEC=$(ComSpec)
+    endif # ComSpec
+endif # COMSPEC
+
+ifdef COMSPEC
+    #### Maybe Windows
+    ifndef CPPCHK_GLIBCXX_DEBUG
+        CPPCHK_GLIBCXX_DEBUG=
+    endif # !CPPCHK_GLIBCXX_DEBUG
+else # !COMSPEC
+    uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
+
+    ifeq ($(uname_S),Linux)
+        ifndef CPPCHK_GLIBCXX_DEBUG
+            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG
+        endif # !CPPCHK_GLIBCXX_DEBUG
+    endif # Linux
+
+    ifeq ($(uname_S),GNU/kFreeBSD)
+        ifndef CPPCHK_GLIBCXX_DEBUG
+            CPPCHK_GLIBCXX_DEBUG=-D_GLIBCXX_DEBUG
+        endif # !CPPCHK_GLIBCXX_DEBUG
+    endif # GNU/kFreeBSD
+
+endif # COMSPEC
+
 ifndef CXXFLAGS
-    CXXFLAGS=-O2 -DNDEBUG -Wall
+    CXXFLAGS=-pedantic -Wall -Wextra -Wabi -Wcast-qual -Wfloat-equal -Winline -Wmissing-declarations -Wmissing-format-attribute -Wno-long-long -Woverloaded-virtual -Wpacked -Wredundant-decls -Wshadow -Wsign-promo $(CPPCHK_GLIBCXX_DEBUG) -g
 endif
 
 ifeq ($(HAVE_RULES),yes)