diff --git a/extensions/resteasy-reactive/rest-client/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/ProxyAddressUtil.java b/extensions/resteasy-reactive/rest-client/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/ProxyAddressUtil.java
index d2a8b55c2f98b4..18cd0d3f4e3b46 100644
--- a/extensions/resteasy-reactive/rest-client/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/ProxyAddressUtil.java
+++ b/extensions/resteasy-reactive/rest-client/runtime/src/main/java/io/quarkus/rest/client/reactive/runtime/ProxyAddressUtil.java
@@ -12,7 +12,7 @@ public static HostAndPort parseAddress(String proxyString) {
         String host = proxyString.substring(0, lastColonIndex);
         int port;
         try {
-            port = Integer.parseInt(proxyString.substring(lastColonIndex + 1));
+            port = Integer.parseInt(proxyString.trim().substring(lastColonIndex + 1));
         } catch (NumberFormatException e) {
             throw new RuntimeException("Invalid proxy setting. The port is not a number in '" + proxyString + "'", e);
         }