diff --git a/testing/memory.cu b/testing/memory.cu
index 622b06a0a..e4c1da8f6 100644
--- a/testing/memory.cu
+++ b/testing/memory.cu
@@ -92,7 +92,7 @@ get_temporary_buffer(my_new_temporary_allocation_system, std::ptrdiff_t)
 }
 
 template<typename Pointer>
-void return_temporary_buffer(my_new_temporary_allocation_system, Pointer p)
+void return_temporary_buffer(my_new_temporary_allocation_system, Pointer)
 {
   // This should never be called (the three-argument with size overload below
   // should be preferred) and shouldn't be ambiguous.
diff --git a/thrust/random/detail/normal_distribution_base.h b/thrust/random/detail/normal_distribution_base.h
index 2a3bd4470..94b966351 100644
--- a/thrust/random/detail/normal_distribution_base.h
+++ b/thrust/random/detail/normal_distribution_base.h
@@ -46,12 +46,12 @@ template<typename RealType>
     __host__ __device__
     RealType sample(UniformRandomNumberGenerator &urng, const RealType mean, const RealType stddev)
     {
-      typedef typename UniformRandomNumberGenerator::result_type uint_type;
-      const uint_type urng_range = UniformRandomNumberGenerator::max - UniformRandomNumberGenerator::min;
+      using uint_type = typename UniformRandomNumberGenerator::result_type;
+      constexpr uint_type urng_range = UniformRandomNumberGenerator::max - UniformRandomNumberGenerator::min;
 
       // Constants for conversion
-      const RealType S1 = static_cast<RealType>(1) / urng_range;
-      const RealType S2 = S1 / 2;
+      constexpr RealType S1 = static_cast<RealType>(1. / static_cast<double>(urng_range));
+      constexpr RealType S2 = S1 / 2;
 
       RealType S3 = static_cast<RealType>(-1.4142135623730950488016887242097); // -sqrt(2)
 
diff --git a/thrust/system/tbb/detail/merge.inl b/thrust/system/tbb/detail/merge.inl
index bcc728546..a85bee163 100644
--- a/thrust/system/tbb/detail/merge.inl
+++ b/thrust/system/tbb/detail/merge.inl
@@ -225,7 +225,7 @@ template<typename DerivedPolicy,
          typename InputIterator2,
          typename OutputIterator,
          typename StrictWeakOrdering>
-OutputIterator merge(execution_policy<DerivedPolicy> &exec,
+OutputIterator merge(execution_policy<DerivedPolicy> &,
                      InputIterator1 first1,
                      InputIterator1 last1,
                      InputIterator2 first2,
@@ -254,7 +254,7 @@ template <typename DerivedPolicy,
           typename OutputIterator2,
           typename StrictWeakOrdering>
 thrust::pair<OutputIterator1,OutputIterator2>
-  merge_by_key(execution_policy<DerivedPolicy> &exec,
+  merge_by_key(execution_policy<DerivedPolicy> &,
                InputIterator1 keys_first1,
                InputIterator1 keys_last1,
                InputIterator2 keys_first2,
diff --git a/thrust/system/tbb/detail/reduce.inl b/thrust/system/tbb/detail/reduce.inl
index 22a13f63d..bef54f5e2 100644
--- a/thrust/system/tbb/detail/reduce.inl
+++ b/thrust/system/tbb/detail/reduce.inl
@@ -100,7 +100,7 @@ template<typename DerivedPolicy,
          typename InputIterator, 
          typename OutputType,
          typename BinaryFunction>
-  OutputType reduce(execution_policy<DerivedPolicy> &exec,
+  OutputType reduce(execution_policy<DerivedPolicy> &,
                     InputIterator begin,
                     InputIterator end,
                     OutputType init,