diff --git a/source/blender/nodes/intern/CMP_nodes/CMP_math.c b/source/blender/nodes/intern/CMP_nodes/CMP_math.c
index e7b548052ee..e909b5a3ae3 100644
--- a/source/blender/nodes/intern/CMP_nodes/CMP_math.c
+++ b/source/blender/nodes/intern/CMP_nodes/CMP_math.c
@@ -140,31 +140,25 @@ static void node_composit_exec_math(void *data, bNode *node, bNodeStack **in, bN
 	CompBuf *cbuf=in[0]->data;
 	CompBuf *cbuf2=in[1]->data;
 	CompBuf *stackbuf; 
-	int maxx=-1, maxy=-1;
 
-	/* stack order out: bw */
-	/* stack order in: col */
-	
-	if(out[0]->hasoutput==0)
-		return;
-	/* check max size */
+	/* check for inputs and outputs for early out*/
+	if(in[0]->hasinput==0 || in[1]->hasinput==0) return;
+	if(in[0]->data==NULL && in[1]->data==NULL) return;
+	if(out[0]->hasoutput==0) return;
+
+	/*create output based on first input */
 	if(cbuf) {
-		maxx=cbuf->x;
-		maxy=cbuf->y;
+		stackbuf=alloc_compbuf(cbuf->x, cbuf->y, CB_VAL, 1);
 	}
-	if(cbuf2) {
-		if(cbuf2->x > maxx) maxx=cbuf2->x;
-		if(cbuf2->y > maxy) maxy=cbuf2->y;
+	/* and if it doesn't exist use the second input since we 
+ 	know that one of them must exist at this point*/
+	else  {
+		stackbuf=alloc_compbuf(cbuf2->x, cbuf2->y, CB_VAL, 1);
 	}
 
 	/* operate in case there's valid size */
-	if((maxx != -1) && (maxy !=-1)) {
-		stackbuf=alloc_compbuf(maxx, maxy, CB_VAL, 1); /* allocs */
-	
-		composit2_pixel_processor(node, stackbuf, in[0]->data, in[0]->vec, in[1]->data, in[1]->vec, do_math, CB_VAL, CB_VAL);
-		
-		out[0]->data= stackbuf;
-	}
+	composit2_pixel_processor(node, stackbuf, in[0]->data, in[0]->vec, in[1]->data, in[1]->vec, do_math, CB_VAL, CB_VAL);
+	out[0]->data= stackbuf;
 }
 
 bNodeType cmp_node_math= {