diff --git a/include/ceres/fpclassify.h b/include/ceres/fpclassify.h
index b730832..e7f0d7c 100644
--- a/include/ceres/fpclassify.h
+++ b/include/ceres/fpclassify.h
@@ -46,6 +46,7 @@
 namespace ceres {
 
 #if defined(_MSC_VER)
+
 inline bool IsFinite  (double x) { return _finite(x);                }
 inline bool IsInfinite(double x) { return !_finite(x) && !_isnan(x); }
 inline bool IsNaN     (double x) { return _isnan(x);                 }
@@ -54,17 +55,15 @@
   return classification == _FPCLASS_NN ||
          classification == _FPCLASS_PN;
 }
-#elif defined(ANDROID)
 
-// On Android when using the GNU STL, the C++ fpclassify functions are not
-// available. Strictly speaking, the std functions are are not standard until
-// C++11. Instead use the C99 macros on Android.
+#elif defined(ANDROID) && defined(_STLPORT_VERSION)
+
+// On Android, when using the STLPort, the C++ isnan and isnormal functions
+// are defined as macros.
 inline bool IsNaN     (double x) { return isnan(x);    }
 inline bool IsNormal  (double x) { return isnormal(x); }
-
 // On Android NDK r6, when using STLPort, the isinf and isfinite functions are
 // not available, so reimplement them.
-#  if defined(_STLPORT_VERSION)
 inline bool IsInfinite(double x) {
   return x ==  std::numeric_limits<double>::infinity() ||
          x == -std::numeric_limits<double>::infinity();
@@ -72,17 +71,15 @@
 inline bool IsFinite(double x) {
   return !isnan(x) && !IsInfinite(x);
 }
-#  else
-inline bool IsFinite  (double x) { return isfinite(x); }
-inline bool IsInfinite(double x) { return isinf(x);    }
-#  endif  // defined(_STLPORT_VERSION)
-#else
+
+# else
+
 // These definitions are for the normal Unix suspects.
-// TODO(keir): Test the "else" with more platforms.
 inline bool IsFinite  (double x) { return std::isfinite(x); }
 inline bool IsInfinite(double x) { return std::isinf(x);    }
 inline bool IsNaN     (double x) { return std::isnan(x);    }
 inline bool IsNormal  (double x) { return std::isnormal(x); }
+
 #endif
 
 }  // namespace ceres
diff --git a/include/ceres/internal/port.h b/include/ceres/internal/port.h
index 4d0bbc0..13db149 100644
--- a/include/ceres/internal/port.h
+++ b/include/ceres/internal/port.h
@@ -33,7 +33,7 @@
 
 #include <string>
 
-#if defined(CERES_TR1_SHARED_PTR)
+#if defined(CERES_SHARED_PTR_IN_TR1_NAMESPACE)
 #include <tr1/memory>
 #else
 #include <memory>
@@ -51,7 +51,7 @@
 // "string" implementation in the global namespace.
 using std::string;
 
-#if defined(CERES_STD_SHARED_PTR_IN_TR1_NAMESPACE) || defined(SHARED_PTR_IN_TR1_NAMESPACE)
+#if defined(CERES_STD_SHARED_PTR_IN_TR1_NAMESPACE) || defined(CERES_SHARED_PTR_IN_TR1_NAMESPACE)
 using std::tr1::shared_ptr;
 #else
 using std::shared_ptr;