diff --git a/src/OpenGL/libGLES_CM/libGLES_CM.cpp b/src/OpenGL/libGLES_CM/libGLES_CM.cpp
index 7e5247c..c7cf691 100644
--- a/src/OpenGL/libGLES_CM/libGLES_CM.cpp
+++ b/src/OpenGL/libGLES_CM/libGLES_CM.cpp
@@ -607,7 +607,7 @@
 
 	if(context)
 	{
-		context->setColorMask(red == GL_TRUE, green == GL_TRUE, blue == GL_TRUE, alpha == GL_TRUE);
+		context->setColorMask(red != GL_FALSE, green != GL_FALSE, blue != GL_FALSE, alpha != GL_FALSE);
 	}
 }
 
@@ -649,7 +649,7 @@
 
 	if(context)
 	{
-		context->setVertexAttribState(index, context->getArrayBuffer(), size, type, (normalized == GL_TRUE), stride, ptr);
+		context->setVertexAttribState(index, context->getArrayBuffer(), size, type, (normalized != GL_FALSE), stride, ptr);
 	}
 }
 
@@ -3473,7 +3473,7 @@
 
 	if(context)
 	{
-		context->setSampleCoverageParams(es1::clamp01(value), invert == GL_TRUE);
+		context->setSampleCoverageParams(es1::clamp01(value), invert != GL_FALSE);
 	}
 }
 
diff --git a/src/OpenGL/libGLESv2/libGLESv2.cpp b/src/OpenGL/libGLESv2/libGLESv2.cpp
index d8a4a8f..fed303f 100644
--- a/src/OpenGL/libGLESv2/libGLESv2.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv2.cpp
@@ -650,7 +650,7 @@
 
 	if(context)
 	{
-		context->setColorMask(red == GL_TRUE, green == GL_TRUE, blue == GL_TRUE, alpha == GL_TRUE);
+		context->setColorMask(red != GL_FALSE, green != GL_FALSE, blue != GL_FALSE, alpha != GL_FALSE);
 	}
 }
 
@@ -4239,7 +4239,7 @@
 
 	if(context)
 	{
-		context->setSampleCoverageParams(es2::clamp01(value), invert == GL_TRUE);
+		context->setSampleCoverageParams(es2::clamp01(value), invert != GL_FALSE);
 	}
 }
 
@@ -5624,7 +5624,7 @@
 			return error(GL_INVALID_OPERATION);
 		}
 
-		context->setVertexAttribState(index, context->getArrayBuffer(), size, type, (normalized == GL_TRUE), false, stride, ptr);
+		context->setVertexAttribState(index, context->getArrayBuffer(), size, type, (normalized != GL_FALSE), false, stride, ptr);
 	}
 }
 
diff --git a/src/OpenGL/libGLESv2/libGLESv3.cpp b/src/OpenGL/libGLESv2/libGLESv3.cpp
index 89055d8..ce2a3c8 100644
--- a/src/OpenGL/libGLESv2/libGLESv3.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv3.cpp
@@ -3679,7 +3679,7 @@
 				}
 
 				es2::Texture2D *texture = context->getTexture2D(target);
-				if(!texture || texture->name == 0 || texture->getImmutableFormat() == GL_TRUE)
+				if(!texture || texture->name == 0 || texture->getImmutableFormat() != GL_FALSE)
 				{
 					return error(GL_INVALID_OPERATION);
 				}
@@ -3754,7 +3754,7 @@
 				}
 
 				es2::Texture3D *texture = context->getTexture3D();
-				if(!texture || texture->name == 0 || texture->getImmutableFormat() == GL_TRUE)
+				if(!texture || texture->name == 0 || texture->getImmutableFormat() != GL_FALSE)
 				{
 					return error(GL_INVALID_OPERATION);
 				}