diff --git a/plugins/GSdx/GLLoader.cpp b/plugins/GSdx/GLLoader.cpp
index 46825cc2c7..7f5badecf7 100644
--- a/plugins/GSdx/GLLoader.cpp
+++ b/plugins/GSdx/GLLoader.cpp
@@ -184,7 +184,7 @@ namespace ReplaceGL {
 
 	void APIENTRY ViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h)
 	{
-		glViewport(x, y, w, h);
+		glViewport(GLint(x), GLint(y), GLsizei(w), GLsizei(h));
 	}
 }
 
diff --git a/plugins/GSdx/GSDeviceOGL.cpp b/plugins/GSdx/GSDeviceOGL.cpp
index f83c944bc0..31e6367005 100644
--- a/plugins/GSdx/GSDeviceOGL.cpp
+++ b/plugins/GSdx/GSDeviceOGL.cpp
@@ -163,7 +163,7 @@ void GSDeviceOGL::GenerateProfilerData()
 	double ms       = 0.000001;
 
 	float replay    = (float)(theApp.GetConfigI("linux_replay"));
-	int first_query = (float)m_profiler.last_query / replay;
+	int first_query = static_cast<int>((float)m_profiler.last_query / replay);
 
 	glGetQueryObjectui64v(m_profiler.timer_query[first_query], GL_QUERY_RESULT, &time_start);
 	for (uint32 q = first_query + 1; q < m_profiler.last_query; q++) {
@@ -1658,7 +1658,7 @@ void GSDeviceOGL::OMSetRenderTargets(GSTexture* rt, GSTexture* ds, const GSVecto
 	{
 		GLState::viewport = size;
 		// FIXME ViewportIndexedf or ViewportIndexedfv (GL4.1)
-		glViewportIndexedf(0, 0, 0, size.x, size.y);
+		glViewportIndexedf(0, 0, 0, GLfloat(size.x), GLfloat(size.y));
 	}
 
 	GSVector4i r = scissor ? *scissor : GSVector4i(size).zwxy();
diff --git a/plugins/GSdx/GSRendererOGL.cpp b/plugins/GSdx/GSRendererOGL.cpp
index bb5c86c345..4470ff2409 100644
--- a/plugins/GSdx/GSRendererOGL.cpp
+++ b/plugins/GSdx/GSRendererOGL.cpp
@@ -612,7 +612,7 @@ void GSRendererOGL::EmulateTextureSampler(const GSTextureCache::Source* tex)
 
 	const uint8 wms = m_context->CLAMP.WMS;
 	const uint8 wmt = m_context->CLAMP.WMT;
-	bool complex_wms_wmt = (wms | wmt) & 2;
+	bool complex_wms_wmt = !!((wms | wmt) & 2);
 
 	bool bilinear = m_filter == 2 ? m_vt.IsLinear() : m_filter != 0;
 	bool simple_sample = !tex->m_palette && cpsm.fmt == 0 && !complex_wms_wmt && !psm.depth;
@@ -998,15 +998,15 @@ void GSRendererOGL::DrawPrims(GSTexture* rt, GSTexture* ds, GSTextureCache::Sour
 				// Replace all sprite with a single fullscreen sprite.
 				GSVertex* s = &m_vertex.buff[0];
 
-				s[0].XYZ.X = (16.0f * m_vt.m_min.p.x) + m_context->XYOFFSET.OFX;
-				s[1].XYZ.X = (16.0f * m_vt.m_max.p.x) + m_context->XYOFFSET.OFX;
-				s[0].XYZ.Y = (16.0f * m_vt.m_min.p.y) + m_context->XYOFFSET.OFY;
-				s[1].XYZ.Y = (16.0f * m_vt.m_max.p.y) + m_context->XYOFFSET.OFY;
+				s[0].XYZ.X = static_cast<uint16>((16.0f * m_vt.m_min.p.x) + m_context->XYOFFSET.OFX);
+				s[1].XYZ.X = static_cast<uint16>((16.0f * m_vt.m_max.p.x) + m_context->XYOFFSET.OFX);
+				s[0].XYZ.Y = static_cast<uint16>((16.0f * m_vt.m_min.p.y) + m_context->XYOFFSET.OFY);
+				s[1].XYZ.Y = static_cast<uint16>((16.0f * m_vt.m_max.p.y) + m_context->XYOFFSET.OFY);
 
-				s[0].U     = 16.0f * m_vt.m_min.t.x;
-				s[0].V     = 16.0f * m_vt.m_min.t.y;
-				s[1].U     = 16.0f * m_vt.m_max.t.x;
-				s[1].V     = 16.0f * m_vt.m_max.t.y;
+				s[0].U     = static_cast<uint16>(16.0f * m_vt.m_min.t.x);
+				s[0].V     = static_cast<uint16>(16.0f * m_vt.m_min.t.y);
+				s[1].U     = static_cast<uint16>(16.0f * m_vt.m_max.t.x);
+				s[1].V     = static_cast<uint16>(16.0f * m_vt.m_max.t.y);
 
 				m_vertex.head = m_vertex.tail = m_vertex.next = 2;
 				m_index.tail = 2;