diff --git a/CMakeLists.txt b/CMakeLists.txt
index 341f845..ec104b0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,7 +40,7 @@
   if(MSVC)
     target_compile_options(${target_name} PRIVATE /W4)
   else()
-    target_compile_options(${target_name} PRIVATE -Wall -Wextra -Wconversion)
+    target_compile_options(${target_name} PRIVATE -Wall -Wextra -Wconversion -Wcast-qual)
   endif()
 
   if(PYBIND11_WERROR)
diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index 67ab216..44c961c 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -422,7 +422,7 @@
     template <typename T = type, typename = enable_if_t<is_copy_constructible<T>::value>> static auto make_copy_constructor(const T *value) -> decltype(new T(*value), Constructor(nullptr)) {
         return [](const void *arg) -> void * { return new T(*((const T *) arg)); }; }
     template <typename T = type> static auto make_move_constructor(const T *value) -> decltype(new T(std::move(*((T *) value))), Constructor(nullptr)) {
-        return [](const void *arg) -> void * { return (void *) new T(std::move(*((T *) arg))); }; }
+        return [](const void *arg) -> void * { return (void *) new T(std::move(*const_cast<T *>(reinterpret_cast<const T *>(arg)))); }; }
 #else
     /* Visual Studio 2015's SFINAE implementation doesn't yet handle the above robustly in all situations.
        Use a workaround that only tests for constructibility for now. */
@@ -706,7 +706,7 @@
         return PyUnicode_DecodeLatin1(str, 1, nullptr);
     }
 
-    operator char*() { return success ? (char *) value.c_str() : nullptr; }
+    operator char*() { return success ? const_cast<char *>(value.c_str()) : nullptr; }
     operator char&() { return value[0]; }
 
     static PYBIND11_DESCR name() { return type_descr(_(PYBIND11_STRING_NAME)); }
@@ -729,7 +729,7 @@
         return PyUnicode_FromWideChar(wstr, 1);
     }
 
-    operator wchar_t*() { return success ? (wchar_t *) value.c_str() : nullptr; }
+    operator wchar_t*() { return success ? const_cast<wchar_t *>(value.c_str()) : nullptr; }
     operator wchar_t&() { return value[0]; }
 
     static PYBIND11_DESCR name() { return type_descr(_(PYBIND11_STRING_NAME)); }
diff --git a/include/pybind11/numpy.h b/include/pybind11/numpy.h
index 19facb0..50eb682 100644
--- a/include/pybind11/numpy.h
+++ b/include/pybind11/numpy.h
@@ -357,8 +357,10 @@
         }
 
         auto tmp = reinterpret_steal<object>(api.PyArray_NewFromDescr_(
-            api.PyArray_Type_, descr.release().ptr(), (int) ndim, (Py_intptr_t *) shape.data(),
-            (Py_intptr_t *) strides.data(), const_cast<void *>(ptr), flags, nullptr));
+            api.PyArray_Type_, descr.release().ptr(), (int) ndim,
+            reinterpret_cast<Py_intptr_t *>(const_cast<size_t*>(shape.data())),
+            reinterpret_cast<Py_intptr_t *>(const_cast<size_t*>(strides.data())),
+            const_cast<void *>(ptr), flags, nullptr));
         if (!tmp)
             pybind11_fail("NumPy: unable to create array!");
         if (ptr) {
@@ -382,7 +384,7 @@
     template<typename T> array(const std::vector<size_t>& shape,
                                const std::vector<size_t>& strides,
                                const T* ptr, handle base = handle())
-    : array(pybind11::dtype::of<T>(), shape, strides, (void *) ptr, base) { }
+    : array(pybind11::dtype::of<T>(), shape, strides, (const void *) ptr, base) { }
 
     template <typename T>
     array(const std::vector<size_t> &shape, const T *ptr,
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 006a4ff..f022c0b 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -129,8 +129,9 @@
             detail::process_attributes<Extra...>::precall(call);
 
             /* Get a pointer to the capture object */
-            capture *cap = (capture *) (sizeof(capture) <= sizeof(call.func.data)
-                                        ? &call.func.data : call.func.data[0]);
+            auto data = (sizeof(capture) <= sizeof(call.func.data)
+                         ? &call.func.data : call.func.data[0]);
+            capture *cap = const_cast<capture *>(reinterpret_cast<const capture *>(data));
 
             /* Override policy for rvalues -- always move */
             constexpr auto is_rvalue = !std::is_pointer<Return>::value
@@ -167,7 +168,7 @@
             sizeof(capture) == sizeof(void *);
         if (is_function_ptr) {
             rec->is_stateless = true;
-            rec->data[1] = (void *) &typeid(FunctionType);
+            rec->data[1] = const_cast<void *>(reinterpret_cast<const void *>(&typeid(FunctionType)));
         }
     }
 
@@ -345,7 +346,7 @@
         /* Install docstring */
         PyCFunctionObject *func = (PyCFunctionObject *) m_ptr;
         if (func->m_ml->ml_doc)
-            std::free((char *) func->m_ml->ml_doc);
+            std::free(const_cast<char *>(func->m_ml->ml_doc));
         func->m_ml->ml_doc = strdup(signatures.c_str());
 
         if (rec->is_method) {
@@ -366,12 +367,12 @@
             std::free((char *) rec->doc);
             std::free((char *) rec->signature);
             for (auto &arg: rec->args) {
-                std::free((char *) arg.name);
-                std::free((char *) arg.descr);
+                std::free(const_cast<char *>(arg.name));
+                std::free(const_cast<char *>(arg.descr));
                 arg.value.dec_ref();
             }
             if (rec->def) {
-                std::free((char *) rec->def->ml_doc);
+                std::free(const_cast<char *>(rec->def->ml_doc));
                 delete rec->def;
             }
             delete rec;
@@ -1666,7 +1667,7 @@
     exception(handle scope, const char *name, PyObject *base = PyExc_Exception) {
         std::string full_name = scope.attr("__name__").cast<std::string>() +
                                 std::string(".") + name;
-        m_ptr = PyErr_NewException((char *) full_name.c_str(), base, NULL);
+        m_ptr = PyErr_NewException(const_cast<char *>(full_name.c_str()), base, NULL);
         if (hasattr(scope, name))
             pybind11_fail("Error during initialization: multiple incompatible "
                           "definitions with name \"" + std::string(name) + "\"");