diff --git a/GNUmakefile b/GNUmakefile
index ac04b31..91145b2 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -1,5 +1,5 @@
 #----------------------------------------------------------------------------
-#  Makefile for d2vsource
+#  Makefile for vs_it, modified based on d2vsource/GNUmakefile
 #----------------------------------------------------------------------------
 
 include config.mak
diff --git a/README.md b/README.md
index 62143a4..2ee3651 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # VapourSynth-IT
 
-VS_IT.dll v0103.1.1 Copyright(C) 2002 thejam79, 2003 minamina, 2014 msg7086
+VS_IT.dll v0103.1.2 Copyright(C) 2002 thejam79, 2003 minamina, 2014 msg7086
 
 VapourSynth Plugin - Inverse Telecine (YV12 Only, IT-0051 base, IT_YV12-0103 base)
 
@@ -28,7 +28,7 @@ VapourSynth Plugin - Inverse Telecine (YV12 Only, IT-0051 base, IT_YV12-0103 bas
 
 ## Usage
 
-    core.it.it(clip clip, int fps = 24, int threshold = 20, int pthreshold = 75)
+    core.it.IT(clip clip, int fps = 24, int threshold = 20, int pthreshold = 75)
 
     clip                      - clip to be processed. Width < 8192 and YV12 only
     fps                       - 24: IVTC; 30: frame-matching only
@@ -41,7 +41,7 @@ VapourSynth Plugin - Inverse Telecine (YV12 Only, IT-0051 base, IT_YV12-0103 bas
 
 ```python
 v = core.std.BlankClip(format=vs.YUV420P8, color=[40,60,240], fpsnum=30000, fpsden=1001)
-v = core.it.it(v)
+v = core.it.IT(v)
 ```
 
 ## Caution
@@ -67,6 +67,7 @@ You are welcome to send PR if you can help to improve the code quality.
 
 ## ChangeLog
 
+- v1.2  14/10/15 Change function name to PascalCase.
 - v1.1  14/10/08 Move 2 thread variables back to object to improve speed. Now we support compiling under Linux using g++ and clang++. Clang version appears to be faster but YMMV.
 - v1.0  14/10/06 All inline asm code has been translated to pure C and SSE2 intrinsics. SSE2 comes with 30% speed up compared to original MMX code.
 - v0.4  14/10/04 Code cleanup. Special thanks to macromizer for cleaning up macros.
diff --git a/configure b/configure
index 9372d1c..9b66ed4 100644
--- a/configure
+++ b/configure
@@ -59,8 +59,8 @@ cc_check()
     fi
     echo "int main(void){$4 return 0;}" >> config.log
     echo "int main(void){$4 return 0;}" >> conftest.cpp
-    echo $CXX conftest.cpp -o conftest $1 $2 >> config.log
-    $CXX conftest.cpp -o conftest $1 $2 2>> config.log
+    echo $CXX conftest.cpp -Werror -o conftest $1 $2 >> config.log
+    $CXX conftest.cpp -Werror -o conftest $1 $2 2>> config.log
     ret=$?
     echo $ret >> config.log
     rm -f conftest*
diff --git a/src/vs_it_interface.cpp b/src/vs_it_interface.cpp
index 5042bc7..aa2b605 100644
--- a/src/vs_it_interface.cpp
+++ b/src/vs_it_interface.cpp
@@ -90,7 +90,7 @@ static void VS_CC itCreate(const VSMap * in, VSMap * out, void * userData, VSCor
 
 	INSTANCE * d = new INSTANCE(new VSVideoInfo(*vi), node, fps, threshold, pthreshold, vsapi);
 
-	vsapi->createFilter(in, out, "it", itInit, itGetFrame, itFree, fmParallel, 0, d, core);
+	vsapi->createFilter(in, out, "IT", itInit, itGetFrame, itFree, fmParallel, 0, d, core);
 	return;
 }
 
@@ -98,7 +98,7 @@ VS_EXTERNAL_API(void) VapourSynthPluginInit(VSConfigPlugin configFunc, VSRegiste
 	configFunc("in.7086.it", "it",
 	           "VapourSynth IVTC Filter v" IT_VERSION,
 	           VAPOURSYNTH_API_VERSION, 1, plugin);
-	registerFunc("it",
+	registerFunc("IT",
 	             "clip:clip;fps:int:opt;threshold:int:opt;pthreshold:int:opt;",
 	             itCreate, nullptr, plugin);
 }
diff --git a/src/vs_it_process.cpp b/src/vs_it_process.cpp
index eee0b6b..2f0793f 100644
--- a/src/vs_it_process.cpp
+++ b/src/vs_it_process.cpp
@@ -345,12 +345,12 @@ bool IT::CompCP(IScriptEnvironment * env) {
 	//1773
 	int thcomb = AdjPara(20);
 	if (n != 0) {
-		if ((env->m_iSumC < thcomb && env->m_iSumP < thcomb) || abs(env->m_iSumC - env->m_iSumP) * 10 < env->m_iSumC + env->m_iSumP) {
-			if (abs(env->m_iSumC - env->m_iSumP) > AdjPara(8)) {
+		if ((env->m_iSumC < thcomb && env->m_iSumP < thcomb) || labs(env->m_iSumC - env->m_iSumP) * 10 < env->m_iSumC + env->m_iSumP) {
+			if (labs(env->m_iSumC - env->m_iSumP) > AdjPara(8)) {
 				env->m_iUseFrame = env->m_iSumP >= env->m_iSumC ? 'c' : 'p';
 				return true;
 			}
-			if (abs(env->m_iSumPC - env->m_iSumPP) > AdjPara(10)) {
+			if (labs(env->m_iSumPC - env->m_iSumPP) > AdjPara(10)) {
 				env->m_iUseFrame = env->m_iSumPP >= env->m_iSumPC ? 'c' : 'p';
 				return true;
 			}