diff --git a/include/boost/config/compiler/borland.hpp b/include/boost/config/compiler/borland.hpp
index 4d59e78e..e49a0a83 100644
--- a/include/boost/config/compiler/borland.hpp
+++ b/include/boost/config/compiler/borland.hpp
@@ -25,7 +25,7 @@
 #endif
 
 // Version 7.0 (Kylix) and below:
-#if (__BORLANDC__ <= 0x570) || !defined(BOOST_STRICT_CONFIG)
+#if (__BORLANDC__ <= 0x570) && !defined(BOOST_STRICT_CONFIG)
 #  define BOOST_NO_INTEGRAL_INT64_T
 #  define BOOST_NO_DEPENDENT_NESTED_DERIVATIONS
 #  define BOOST_NO_PRIVATE_IN_AGGREGATE
diff --git a/include/boost/config/compiler/comeau.hpp b/include/boost/config/compiler/comeau.hpp
index a0e8835a..3020178f 100644
--- a/include/boost/config/compiler/comeau.hpp
+++ b/include/boost/config/compiler/comeau.hpp
@@ -9,7 +9,7 @@
 
 #include "boost/config/compiler/common_edg.hpp"
 
-#if (__COMO_VERSION__ <= 4245) || !defined(BOOST_STRICT_CONFIG)
+#if (__COMO_VERSION__ <= 4245) && !defined(BOOST_STRICT_CONFIG)
 #  if defined(_MSC_VER) && _MSC_VER <= 1300
 #     define BOOST_NO_STDC_NAMESPACE
 #     define BOOST_NO_SWPRINTF
diff --git a/include/boost/config/compiler/hp_acc.hpp b/include/boost/config/compiler/hp_acc.hpp
index 44f79c4f..a51b01a0 100644
--- a/include/boost/config/compiler/hp_acc.hpp
+++ b/include/boost/config/compiler/hp_acc.hpp
@@ -16,7 +16,7 @@
 #  endif
 #endif
 
-#if (__HP_aCC <= 33300) || !defined(BOOST_STRICT_CONFIG)
+#if (__HP_aCC <= 33300) && !defined(BOOST_STRICT_CONFIG)
 // member templates are sufficiently broken that we disable them for now
 #    define BOOST_NO_MEMBER_TEMPLATES
 #    define BOOST_NO_DEPENDENT_NESTED_DERIVATIONS
diff --git a/include/boost/config/compiler/intel.hpp b/include/boost/config/compiler/intel.hpp
index 05b2db0a..4db86f51 100644
--- a/include/boost/config/compiler/intel.hpp
+++ b/include/boost/config/compiler/intel.hpp
@@ -21,7 +21,7 @@
 #  define BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS
 #endif
 
-#if (BOOST_INTEL_CXX_VERSION <= 600) || !defined(BOOST_STRICT_CONFIG)
+#if (BOOST_INTEL_CXX_VERSION <= 600) && !defined(BOOST_STRICT_CONFIG)
 
 #  if defined(_MSC_VER) && (_MSC_VER <= 1300) // added check for <= VC 7 (Peter Dimov)
 
diff --git a/include/boost/config/compiler/kai.hpp b/include/boost/config/compiler/kai.hpp
index a7451936..af91946f 100644
--- a/include/boost/config/compiler/kai.hpp
+++ b/include/boost/config/compiler/kai.hpp
@@ -9,7 +9,7 @@
 
 #include "boost/config/compiler/common_edg.hpp"
 
-#   if (__KCC_VERSION <= 4001) || !defined(BOOST_STRICT_CONFIG)
+#   if (__KCC_VERSION <= 4001) && !defined(BOOST_STRICT_CONFIG)
       // at least on Sun, the contents of <cwchar> is not in namespace std
 #     define BOOST_NO_STDC_NAMESPACE
 #   endif
diff --git a/include/boost/config/compiler/mpw.hpp b/include/boost/config/compiler/mpw.hpp
index 3cd979a0..990db443 100644
--- a/include/boost/config/compiler/mpw.hpp
+++ b/include/boost/config/compiler/mpw.hpp
@@ -18,7 +18,7 @@
 //
 // MPW 8.90:
 //
-#if (MPW_CPLUS <= 0x890) || !defined(BOOST_STRICT_CONFIG)
+#if (MPW_CPLUS <= 0x890) && !defined(BOOST_STRICT_CONFIG)
 #  define BOOST_NO_CV_SPECIALIZATIONS
 #  define BOOST_NO_DEPENDENT_NESTED_DERIVATIONS
 #  define BOOST_NO_DEPENDENT_TYPES_IN_TEMPLATE_VALUE_PARAMETERS
diff --git a/include/boost/config/compiler/sunpro_cc.hpp b/include/boost/config/compiler/sunpro_cc.hpp
index dab038ff..bfc9be60 100644
--- a/include/boost/config/compiler/sunpro_cc.hpp
+++ b/include/boost/config/compiler/sunpro_cc.hpp
@@ -30,7 +30,7 @@
 #      define BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 #    endif
 
-#    if (__SUNPRO_CC <= 0x530) || !defined(BOOST_STRICT_CONFIG)
+#    if (__SUNPRO_CC <= 0x530) && !defined(BOOST_STRICT_CONFIG)
        // SunPro 5.3 has better support for partial specialization,
        // but breaks when compiling std::less<shared_ptr<T> >
        // (Jens Maurer 4 Nov 2001).