diff --git a/Sources/Plasma/CoreLib/HeadSpin.h b/Sources/Plasma/CoreLib/HeadSpin.h
index 76a98e8d..9a4d567a 100644
--- a/Sources/Plasma/CoreLib/HeadSpin.h
+++ b/Sources/Plasma/CoreLib/HeadSpin.h
@@ -238,7 +238,12 @@ inline double hsSwapEndianDouble(double dvalue)
 *   StrPrintf(buffer, arrsize(buffer), "%u", value);
 *
 ***/
-#define  arrsize(a)     (sizeof(a) / sizeof((a)[0]))
+#ifdef HAVE_CONSTEXPR
+    template <typename _T, size_t _Sz>
+    constexpr size_t arrsize(_T(&)[_Sz]) { return _Sz; }
+#else
+#   define  arrsize(a)  (sizeof(a) / sizeof((a)[0]))
+#endif
 
 
 /****************************************************************************
diff --git a/Sources/Plasma/NucleusLib/pnAsyncCoreExe/Private/Win32/pnAceW32Dns.cpp b/Sources/Plasma/NucleusLib/pnAsyncCoreExe/Private/Win32/pnAceW32Dns.cpp
index ce0a9027..e3b4338e 100644
--- a/Sources/Plasma/NucleusLib/pnAsyncCoreExe/Private/Win32/pnAceW32Dns.cpp
+++ b/Sources/Plasma/NucleusLib/pnAsyncCoreExe/Private/Win32/pnAceW32Dns.cpp
@@ -102,7 +102,9 @@ static void LookupProcess (Lookup * lookup, unsigned error) {
     in_addr const * const * const inAddr = (in_addr **) host.h_addr_list;
 
     // allocate a buffer large enough to hold all the addresses
-    size_t count = arrsize(inAddr);
+    size_t count = 0;
+    while (inAddr[count])
+        ++count;
     plNetAddress* addrs = new plNetAddress[count];
 
     // fill in address data
diff --git a/Sources/Plasma/PubUtilLib/plNetClientComm/plNetClientComm.cpp b/Sources/Plasma/PubUtilLib/plNetClientComm/plNetClientComm.cpp
index d16634e7..d5d7447f 100644
--- a/Sources/Plasma/PubUtilLib/plNetClientComm/plNetClientComm.cpp
+++ b/Sources/Plasma/PubUtilLib/plNetClientComm/plNetClientComm.cpp
@@ -561,20 +561,6 @@ static void INetAuthFileListRequestCallback (
     msg->Send();
 }
 
-//============================================================================
-static void INetCliAuthFileRequestCallback (
-    ENetError       result,
-    void *          param,
-    const wchar_t     filename[],
-    hsStream *      writer
-) {
-    plNetCommFileDownloadMsg * msg = new plNetCommFileDownloadMsg;
-    msg->result = result;
-    msg->writer = writer;
-    StrCopy(msg->filename, filename, arrsize(filename));
-    msg->Send();
-}
-
 //============================================================================
 static void INetCliGameJoinAgeRequestCallback (
     ENetError       result,
diff --git a/cmake/CompilerChecks.cmake b/cmake/CompilerChecks.cmake
index 973b671c..11be0d74 100644
--- a/cmake/CompilerChecks.cmake
+++ b/cmake/CompilerChecks.cmake
@@ -58,6 +58,11 @@ try_compile(HAVE_GCC_DEPRECATED_ATTR ${PROJECT_BINARY_DIR}
             COMPILE_DEFINITIONS -DTRY_GCC_ATTR
             OUTPUT_VARIABLE OUTPUT)
 
+# Look for C++11 constexpr support
+try_compile(HAVE_CONSTEXPR ${PROJECT_BINARY_DIR}
+            ${PROJECT_SOURCE_DIR}/cmake/check_constexpr.cpp
+            OUTPUT_VARIABLE OUTPUT)
+
 configure_file(${PROJECT_SOURCE_DIR}/cmake/hsCompilerSpecific.h.cmake
                ${PROJECT_BINARY_DIR}/hsCompilerSpecific.h)
 include_directories(${PROJECT_BINARY_DIR})
diff --git a/cmake/check_constexpr.cpp b/cmake/check_constexpr.cpp
new file mode 100644
index 00000000..bff6467e
--- /dev/null
+++ b/cmake/check_constexpr.cpp
@@ -0,0 +1,6 @@
+constexpr int foo() { return 5; }
+
+int main(int, char **)
+{
+    return foo();
+}
diff --git a/cmake/hsCompilerSpecific.h.cmake b/cmake/hsCompilerSpecific.h.cmake
index 02b8e5d1..242c4cf1 100644
--- a/cmake/hsCompilerSpecific.h.cmake
+++ b/cmake/hsCompilerSpecific.h.cmake
@@ -51,4 +51,6 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #cmakedefine HAVE_CXX14_DEPRECATED_ATTR
 #cmakedefine HAVE_GCC_DEPRECATED_ATTR
 
+#cmakedefine HAVE_CONSTEXPR
+
 #endif