diff --git a/example/src/Layouting/index.tsx b/example/src/Layouting/index.tsx
index 8e4ce5bf..a3b0e7eb 100644
--- a/example/src/Layouting/index.tsx
+++ b/example/src/Layouting/index.tsx
@@ -8,6 +8,8 @@ import ReactFlow, {
   Position,
   useNodesState,
   useEdgesState,
+  MarkerType,
+  EdgeMarker,
 } from 'react-flow-renderer';
 import dagre from 'dagre';
 
@@ -27,9 +29,12 @@ const LayoutFlow = () => {
   const [nodes, setNodes, onNodesChange] = useNodesState(initialItems.nodes);
   const [edges, setEdges, onEdgesChange] = useEdgesState(initialItems.edges);
 
-  const onConnect = useCallback((connection: Connection) => {
-    setEdges((eds) => addEdge(connection, eds));
-  }, []);
+  const onConnect = useCallback(
+    (connection: Connection) => {
+      setEdges((eds) => addEdge(connection, eds));
+    },
+    [setEdges]
+  );
 
   const onLayout = (direction: string) => {
     const isHorizontal = direction === 'LR';
@@ -63,6 +68,17 @@ const LayoutFlow = () => {
     setNodes((nds) => nds.map((n) => ({ ...n, selected: false })));
   };
 
+  const changeMarker = () => {
+    setEdges((eds) =>
+      eds.map((e) => ({
+        ...e,
+        markerEnd: {
+          type: (e.markerEnd as EdgeMarker)?.type === MarkerType.Arrow ? MarkerType.ArrowClosed : MarkerType.Arrow,
+        },
+      }))
+    );
+  };
+
   return (
     <div className="layoutflow">
       <ReactFlowProvider>
@@ -85,6 +101,7 @@ const LayoutFlow = () => {
             horizontal layout
           </button>
           <button onClick={() => unselect()}>unselect nodes</button>
+          <button onClick={() => changeMarker()}>change marker</button>
         </div>
       </ReactFlowProvider>
     </div>
diff --git a/example/src/Layouting/initial-elements.ts b/example/src/Layouting/initial-elements.ts
index ce763320..539a4561 100644
--- a/example/src/Layouting/initial-elements.ts
+++ b/example/src/Layouting/initial-elements.ts
@@ -1,4 +1,4 @@
-import { Node, Edge, XYPosition } from 'react-flow-renderer';
+import { Node, Edge, XYPosition, MarkerType } from 'react-flow-renderer';
 
 const position: XYPosition = { x: 0, y: 0 };
 
@@ -59,16 +59,16 @@ const nodes: Node[] = [
 ];
 
 const edges: Edge[] = [
-  { id: 'e12', source: '1', target: '2', type: 'smoothstep' },
-  { id: 'e13', source: '1', target: '3', type: 'smoothstep' },
-  { id: 'e22a', source: '2', target: '2a', type: 'smoothstep' },
-  { id: 'e22b', source: '2', target: '2b', type: 'smoothstep' },
-  { id: 'e22c', source: '2', target: '2c', type: 'smoothstep' },
-  { id: 'e2c2d', source: '2c', target: '2d', type: 'smoothstep' },
+  { id: 'e12', source: '1', target: '2', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e13', source: '1', target: '3', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e22a', source: '2', target: '2a', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e22b', source: '2', target: '2b', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e22c', source: '2', target: '2c', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e2c2d', source: '2c', target: '2d', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
 
-  { id: 'e45', source: '4', target: '5', type: 'smoothstep' },
-  { id: 'e56', source: '5', target: '6', type: 'smoothstep' },
-  { id: 'e57', source: '5', target: '7', type: 'smoothstep' },
+  { id: 'e45', source: '4', target: '5', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e56', source: '5', target: '6', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
+  { id: 'e57', source: '5', target: '7', type: 'smoothstep', markerEnd: { type: MarkerType.Arrow } },
 ];
 
 const nodesAndEdges = { nodes, edges };
diff --git a/example/src/MultiFlows/index.tsx b/example/src/MultiFlows/index.tsx
index 0a247146..d3213fca 100644
--- a/example/src/MultiFlows/index.tsx
+++ b/example/src/MultiFlows/index.tsx
@@ -9,6 +9,7 @@ import ReactFlow, {
   ReactFlowProvider,
   useNodesState,
   useEdgesState,
+  MarkerType,
 } from 'react-flow-renderer';
 
 import './multiflows.css';
@@ -21,12 +22,12 @@ const initialNodes: Node[] = [
 ];
 
 const initialEdges: Edge[] = [
-  { id: 'e1-2', source: '1', target: '2', animated: true },
+  { id: 'e1-2', source: '1', target: '2', animated: true, markerEnd: { type: MarkerType.Arrow } },
   { id: 'e1-3', source: '1', target: '3' },
 ];
 
-const Flow: FC = () => {
-  const [nodes, setNodes, onNodesChange] = useNodesState(initialNodes);
+const Flow: FC<{ id: string }> = ({ id }) => {
+  const [nodes, , onNodesChange] = useNodesState(initialNodes);
   const [edges, setEdges, onEdgesChange] = useEdgesState(initialEdges);
 
   const onConnect = (params: Edge | Connection) => setEdges((eds) => addEdge(params, eds));
@@ -39,6 +40,7 @@ const Flow: FC = () => {
         onNodesChange={onNodesChange}
         onEdgesChange={onEdgesChange}
         onConnect={onConnect}
+        id={id}
       >
         <Background />
       </ReactFlow>
@@ -48,8 +50,8 @@ const Flow: FC = () => {
 
 const MultiFlows: FC = () => (
   <div className="react-flow__example-multiflows">
-    <Flow />
-    <Flow />
+    <Flow id="flow-a" />
+    <Flow id="flow-b" />
   </div>
 );
 
diff --git a/src/components/Edges/wrapEdge.tsx b/src/components/Edges/wrapEdge.tsx
index 7f2a66b9..4bc74835 100644
--- a/src/components/Edges/wrapEdge.tsx
+++ b/src/components/Edges/wrapEdge.tsx
@@ -53,6 +53,7 @@ export default (EdgeComponent: ComponentType<EdgeProps>) => {
     onEdgeUpdateEnd,
     markerEnd,
     markerStart,
+    rfId,
   }: WrapEdgeProps): JSX.Element | null => {
     const [updating, setUpdating] = useState<boolean>(false);
     const { addSelectedEdges, connectionMode } = useStore(selector, shallow);
@@ -120,8 +121,8 @@ export default (EdgeComponent: ComponentType<EdgeProps>) => {
 
     const onEdgeUpdaterMouseEnter = () => setUpdating(true);
     const onEdgeUpdaterMouseOut = () => setUpdating(false);
-    const markerStartUrl = useMemo(() => `url(#${getMarkerId(markerStart)})`, [markerStart]);
-    const markerEndUrl = useMemo(() => `url(#${getMarkerId(markerEnd)})`, [markerEnd]);
+    const markerStartUrl = useMemo(() => `url(#${getMarkerId(markerStart, rfId)})`, [markerStart, rfId]);
+    const markerEndUrl = useMemo(() => `url(#${getMarkerId(markerEnd, rfId)})`, [markerEnd, rfId]);
 
     if (hidden) {
       return null;
diff --git a/src/container/EdgeRenderer/MarkerDefinitions.tsx b/src/container/EdgeRenderer/MarkerDefinitions.tsx
index dcae27bf..4075ec2e 100644
--- a/src/container/EdgeRenderer/MarkerDefinitions.tsx
+++ b/src/container/EdgeRenderer/MarkerDefinitions.tsx
@@ -1,4 +1,4 @@
-import React, { useMemo } from 'react';
+import React, { memo, useCallback } from 'react';
 
 import { useStore } from '../../store';
 import { EdgeMarker, ReactFlowState } from '../../types';
@@ -9,6 +9,7 @@ interface MarkerProps extends EdgeMarker {
 }
 interface MarkerDefinitionsProps {
   defaultColor: string;
+  rfId?: string;
 }
 
 const Marker = ({
@@ -40,26 +41,36 @@ const Marker = ({
   );
 };
 
-const edgesSelector = (s: ReactFlowState) => s.edges;
-
-const MarkerDefinitions = ({ defaultColor }: MarkerDefinitionsProps) => {
-  const edges = useStore(edgesSelector);
-  const markers = useMemo(() => {
+const markerSelector =
+  ({ defaultColor, rfId }: { defaultColor: string; rfId?: string }) =>
+  (s: ReactFlowState) => {
     const ids: string[] = [];
 
-    return edges.reduce<MarkerProps[]>((markers, edge) => {
-      [edge.markerStart, edge.markerEnd].forEach((marker) => {
-        if (marker && typeof marker === 'object') {
-          const markerId = getMarkerId(marker);
-          if (!ids.includes(markerId)) {
-            markers.push({ id: markerId, color: marker.color || defaultColor, ...marker });
-            ids.push(markerId);
+    return s.edges
+      .reduce<MarkerProps[]>((markers, edge) => {
+        [edge.markerStart, edge.markerEnd].forEach((marker) => {
+          if (marker && typeof marker === 'object') {
+            const markerId = getMarkerId(marker, rfId);
+            if (!ids.includes(markerId)) {
+              markers.push({ id: markerId, color: marker.color || defaultColor, ...marker });
+              ids.push(markerId);
+            }
           }
-        }
-      });
-      return markers.sort((a, b) => a.id.localeCompare(b.id));
-    }, []);
-  }, [edges, defaultColor]);
+        });
+        return markers;
+      }, [])
+      .sort((a, b) => a.id.localeCompare(b.id));
+  };
+
+// when you have multiple flows on a page and you hide the first one, the other ones have no markers anymore
+// when they do have markers with the same ids. To prevent this the user can pass a unique id to the react flow wrapper
+// that we can then use for creating our unique marker ids
+const MarkerDefinitions = ({ defaultColor, rfId }: MarkerDefinitionsProps) => {
+  const markers = useStore(
+    useCallback(markerSelector({ defaultColor, rfId }), [defaultColor, rfId]),
+    // the id includes all marker options, so we just need to look at that part of the marker
+    (a, b) => !(a.length !== b.length || a.some((m, i) => m.id !== b[i].id))
+  );
 
   return (
     <defs>
@@ -82,4 +93,4 @@ const MarkerDefinitions = ({ defaultColor }: MarkerDefinitionsProps) => {
 
 MarkerDefinitions.displayName = 'MarkerDefinitions';
 
-export default MarkerDefinitions;
+export default memo(MarkerDefinitions);
diff --git a/src/container/EdgeRenderer/index.tsx b/src/container/EdgeRenderer/index.tsx
index 4ddb9909..98f90b1d 100644
--- a/src/container/EdgeRenderer/index.tsx
+++ b/src/container/EdgeRenderer/index.tsx
@@ -40,6 +40,7 @@ interface EdgeRendererProps {
   edgeUpdaterRadius?: number;
   noPanClassName?: string;
   elevateEdgesOnSelect: boolean;
+  rfId?: string;
 }
 
 const selector = (s: ReactFlowState) => ({
@@ -93,7 +94,7 @@ const EdgeRenderer = (props: EdgeRendererProps) => {
           height={height}
           className="react-flow__edges react-flow__container"
         >
-          {isMaxLevel && <MarkerDefinitions defaultColor={defaultMarkerColor} />}
+          {isMaxLevel && <MarkerDefinitions defaultColor={defaultMarkerColor} rfId={props.rfId} />}
           <g>
             {edges.map((edge: Edge) => {
               const [sourceNodeRect, sourceHandleBounds, sourceIsValid] = getNodeData(nodeInternals, edge.source);
@@ -184,6 +185,7 @@ const EdgeRenderer = (props: EdgeRendererProps) => {
                   onEdgeDoubleClick={props.onEdgeDoubleClick}
                   onEdgeUpdateStart={props.onEdgeUpdateStart}
                   onEdgeUpdateEnd={props.onEdgeUpdateEnd}
+                  rfId={props.rfId}
                 />
               );
             })}
diff --git a/src/container/GraphView/index.tsx b/src/container/GraphView/index.tsx
index e5db5604..3ef21baf 100644
--- a/src/container/GraphView/index.tsx
+++ b/src/container/GraphView/index.tsx
@@ -84,6 +84,7 @@ const GraphView = ({
   noWheelClassName,
   noPanClassName,
   elevateEdgesOnSelect,
+  id,
 }: GraphViewProps) => {
   useOnInitHandler(onInit);
 
@@ -139,6 +140,7 @@ const GraphView = ({
           defaultMarkerColor={defaultMarkerColor}
           noPanClassName={noPanClassName}
           elevateEdgesOnSelect={!!elevateEdgesOnSelect}
+          rfId={id}
         />
         <NodeRenderer
           nodeTypes={nodeTypes}
diff --git a/src/container/ReactFlow/index.tsx b/src/container/ReactFlow/index.tsx
index 681e8abb..3e815045 100644
--- a/src/container/ReactFlow/index.tsx
+++ b/src/container/ReactFlow/index.tsx
@@ -211,6 +211,7 @@ const ReactFlow = forwardRef<ReactFlowRefType, ReactFlowProps>(
             noWheelClassName={noWheelClassName}
             noPanClassName={noPanClassName}
             elevateEdgesOnSelect={elevateEdgesOnSelect}
+            id={rest?.id}
           />
           <StoreUpdater
             nodes={nodes}
diff --git a/src/types/edges.ts b/src/types/edges.ts
index d8e6813a..478c1b7d 100644
--- a/src/types/edges.ts
+++ b/src/types/edges.ts
@@ -121,6 +121,7 @@ export interface WrapEdgeProps<T = any> {
   onEdgeUpdateEnd?: (event: MouseEvent, edge: Edge, handleType: HandleType) => void;
   markerStart?: EdgeMarkerType;
   markerEnd?: EdgeMarkerType;
+  rfId?: string;
 }
 
 export interface EdgeSmoothStepProps<T = any> extends EdgeProps<T> {
diff --git a/src/utils/graph.ts b/src/utils/graph.ts
index a426baed..fce21b3c 100644
--- a/src/utils/graph.ts
+++ b/src/utils/graph.ts
@@ -30,7 +30,7 @@ export const getIncomers = <T = any, U extends T = T>(node: Node<U>, nodes: Node
 const getEdgeId = ({ source, sourceHandle, target, targetHandle }: Connection): string =>
   `reactflow__edge-${source}${sourceHandle || ''}-${target}${targetHandle || ''}`;
 
-export const getMarkerId = (marker: EdgeMarkerType | undefined): string => {
+export const getMarkerId = (marker: EdgeMarkerType | undefined, rfId?: string): string => {
   if (typeof marker === 'undefined') {
     return '';
   }
@@ -39,10 +39,12 @@ export const getMarkerId = (marker: EdgeMarkerType | undefined): string => {
     return marker;
   }
 
-  return Object.keys(marker)
+  const idPrefix = rfId ? `${rfId}__` : '';
+
+  return `${idPrefix}${Object.keys(marker)
     .sort()
     .map((key: string) => `${key}=${(marker as any)[key]}`)
-    .join('&');
+    .join('&')}`;
 };
 
 const connectionExists = (edge: Edge, edges: Edge[]) => {