diff --git a/sim/instructions/instructions.ts b/sim/instructions/instructions.ts
index 1a91b9c3..e0798089 100644
--- a/sim/instructions/instructions.ts
+++ b/sim/instructions/instructions.ts
@@ -59,7 +59,7 @@ namespace pxsim.instructions {
                 border-color: ${BORDER_COLOR};
                 border-style: solid;
                 border-radius: ${BORDER_RADIUS}px;
-                display: block;
+                display: inline-block;
                 width: ${PANEL_WIDTH}px;
                 height: ${PANEL_HEIGHT}px;
                 position: relative;