diff --git a/rskj-core/src/main/java/org/ethereum/rpc/Web3Impl.java b/rskj-core/src/main/java/org/ethereum/rpc/Web3Impl.java
index 8bb6f3195cd..e91578400b4 100644
--- a/rskj-core/src/main/java/org/ethereum/rpc/Web3Impl.java
+++ b/rskj-core/src/main/java/org/ethereum/rpc/Web3Impl.java
@@ -281,7 +281,7 @@ public String rsk_protocolVersion() {
                 }
             }
 
-            return s = Integer.toString(version);
+            return s = HexUtils.toQuantityJsonHex(version);
         } finally {
             if (logger.isDebugEnabled()) {
                 logger.debug("rsk_protocolVersion(): {}", s);
diff --git a/rskj-core/src/test/java/org/ethereum/rpc/Web3ImplTest.java b/rskj-core/src/test/java/org/ethereum/rpc/Web3ImplTest.java
index 09281d716b5..f0e17ed66c6 100644
--- a/rskj-core/src/test/java/org/ethereum/rpc/Web3ImplTest.java
+++ b/rskj-core/src/test/java/org/ethereum/rpc/Web3ImplTest.java
@@ -153,7 +153,7 @@ void eth_protocolVersion() {
 
         String netVersion = web3.eth_protocolVersion();
 
-        assertEquals(0, netVersion.compareTo("1"), "RSK net version different than one");
+        assertEquals(0, netVersion.compareTo("0x1"), "RSK net version different than one");
     }
 
     @Test