diff --git a/core-common/src/main/java11/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java b/core-common/src/main/java11/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
index ef22ed2a0bf..f774e4f37ad 100644
--- a/core-common/src/main/java11/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
+++ b/core-common/src/main/java11/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
@@ -31,9 +31,4 @@ public void cancel() {
             }
         });
     }
-
-    static boolean isSubscriber(Class<?> clazz) {
-        return java.util.concurrent.Flow.Subscriber.class.equals(clazz)
-                || org.glassfish.jersey.internal.jsr166.Flow.Subscriber.class.equals(clazz);
-    }
 }
diff --git a/core-common/src/main/java8/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java b/core-common/src/main/java8/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
index 1fbb3d301a2..dd25372cfc4 100644
--- a/core-common/src/main/java8/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
+++ b/core-common/src/main/java8/org/glassfish/jersey/internal/jsr166/JerseyFlowSubscriber.java
@@ -17,7 +17,4 @@
 package org.glassfish.jersey.internal.jsr166;
 
 public interface JerseyFlowSubscriber<T> extends Flow.Subscriber<T> {
-    static boolean isSubscriber(Class<?> clazz) {
-        return org.glassfish.jersey.internal.jsr166.Flow.Subscriber.class.equals(clazz);
-    }
 }
diff --git a/core-server/src/main/java/org/glassfish/jersey/server/model/IntrospectionModeller.java b/core-server/src/main/java/org/glassfish/jersey/server/model/IntrospectionModeller.java
index c1c6d25f3b1..b2a42c9698a 100644
--- a/core-server/src/main/java/org/glassfish/jersey/server/model/IntrospectionModeller.java
+++ b/core-server/src/main/java/org/glassfish/jersey/server/model/IntrospectionModeller.java
@@ -40,16 +40,15 @@
 import javax.ws.rs.container.AsyncResponse;
 import javax.ws.rs.container.Suspended;
 import javax.ws.rs.core.MediaType;
-import javax.ws.rs.sse.SseEventSink;
 
 import org.glassfish.jersey.internal.Errors;
-import org.glassfish.jersey.internal.jsr166.JerseyFlowSubscriber;
 import org.glassfish.jersey.internal.util.Producer;
 import org.glassfish.jersey.internal.util.ReflectionHelper;
 import org.glassfish.jersey.internal.util.Tokenizer;
 import org.glassfish.jersey.server.ManagedAsync;
 import org.glassfish.jersey.server.internal.LocalizationMessages;
 import org.glassfish.jersey.server.model.internal.ModelHelper;
+import org.glassfish.jersey.server.model.internal.SseTypeResolver;
 
 /**
  * Utility class for constructing resource model from JAX-RS annotated POJO.
@@ -299,7 +298,7 @@ private static void introspectAsyncFeatures(AnnotatedMethod am, ResourceMethod.B
         }
 
         for (Class<?> paramType : am.getParameterTypes()) {
-            if (JerseyFlowSubscriber.isSubscriber(paramType) || SseEventSink.class.equals(paramType)) {
+            if (SseTypeResolver.isSseSinkParam(paramType)) {
                 resourceMethodBuilder.sse();
             }
         }
diff --git a/core-server/src/main/java/org/glassfish/jersey/server/model/ResourceMethodValidator.java b/core-server/src/main/java/org/glassfish/jersey/server/model/ResourceMethodValidator.java
index 30c78447a1b..aa20dc8a1ec 100644
--- a/core-server/src/main/java/org/glassfish/jersey/server/model/ResourceMethodValidator.java
+++ b/core-server/src/main/java/org/glassfish/jersey/server/model/ResourceMethodValidator.java
@@ -37,12 +37,11 @@
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
 import javax.ws.rs.QueryParam;
-import javax.ws.rs.sse.SseEventSink;
 
 import org.glassfish.jersey.internal.Errors;
-import org.glassfish.jersey.internal.jsr166.JerseyFlowSubscriber;
 import org.glassfish.jersey.server.ContainerRequest;
 import org.glassfish.jersey.server.internal.LocalizationMessages;
+import org.glassfish.jersey.server.model.internal.SseTypeResolver;
 import org.glassfish.jersey.server.spi.internal.ParameterValueHelper;
 import org.glassfish.jersey.server.spi.internal.ValueParamProvider;
 
@@ -86,8 +85,7 @@ private void checkMethod(ResourceMethod method) {
         if ("GET".equals(method.getHttpMethod())) {
             final long eventSinkCount = invocable.getParameters()
                     .stream()
-                    .filter(parameter -> JerseyFlowSubscriber.isSubscriber(parameter.getRawType())
-                            || SseEventSink.class.equals(parameter.getRawType()))
+                    .filter(parameter -> SseTypeResolver.isSseSinkParam(parameter.getRawType()))
                     .count();
 
             final boolean isSse = eventSinkCount > 0;
@@ -216,8 +214,7 @@ private void checkParameters(ResourceMethod method) {
 
     private boolean isSseInjected(final Invocable invocable) {
         return invocable.getParameters().stream()
-                .anyMatch(parameter -> JerseyFlowSubscriber.isSubscriber(parameter.getRawType())
-                        || SseEventSink.class.equals(parameter.getRawType()));
+                .anyMatch(parameter -> SseTypeResolver.isSseSinkParam(parameter.getRawType()));
     }
 
     private static final Set<Class> PARAM_ANNOTATION_SET = createParamAnnotationSet();
diff --git a/core-server/src/main/java/org/glassfish/jersey/server/model/internal/JavaResourceMethodDispatcherProvider.java b/core-server/src/main/java/org/glassfish/jersey/server/model/internal/JavaResourceMethodDispatcherProvider.java
index bf297729348..c4598ac7d20 100644
--- a/core-server/src/main/java/org/glassfish/jersey/server/model/internal/JavaResourceMethodDispatcherProvider.java
+++ b/core-server/src/main/java/org/glassfish/jersey/server/model/internal/JavaResourceMethodDispatcherProvider.java
@@ -28,7 +28,6 @@
 import javax.ws.rs.core.Response;
 import javax.ws.rs.sse.SseEventSink;
 
-import org.glassfish.jersey.internal.jsr166.JerseyFlowSubscriber;
 import org.glassfish.jersey.server.ContainerRequest;
 import org.glassfish.jersey.server.internal.inject.ConfiguredValidator;
 import org.glassfish.jersey.server.model.Invocable;
@@ -77,8 +76,7 @@ public ResourceMethodDispatcher create(final Invocable resourceMethod,
             // return type is void
             int i = 0;
             for (final Parameter parameter : resourceMethod.getParameters()) {
-                if (JerseyFlowSubscriber.isSubscriber(parameter.getRawType())
-                        || SseEventSink.class.equals(parameter.getRawType())) {
+                if (SseTypeResolver.isSseSinkParam(parameter.getRawType())) {
                     resourceMethodDispatcher =
                             new SseEventSinkInvoker(resourceMethod, invocationHandler, valueProviders, validator, i);
                     break;
diff --git a/core-server/src/main/java/org/glassfish/jersey/server/model/internal/SseTypeResolver.java b/core-server/src/main/java/org/glassfish/jersey/server/model/internal/SseTypeResolver.java
new file mode 100644
index 00000000000..6a4f557661a
--- /dev/null
+++ b/core-server/src/main/java/org/glassfish/jersey/server/model/internal/SseTypeResolver.java
@@ -0,0 +1,28 @@
+package org.glassfish.jersey.server.model.internal;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+public class SseTypeResolver {
+
+    private static final Set<Class<?>> SUPPORTED_SSE_SINK_TYPES;
+
+    static {
+        Set<Class<?>> set = new HashSet<>(8);
+
+        set.add(org.glassfish.jersey.internal.jsr166.Flow.Subscriber.class);
+        set.add(javax.ws.rs.sse.SseEventSink.class);
+        try {
+            Class<?> clazz = Class.forName("java.util.concurrent.Flow.Subscriber");
+            set.add(clazz);
+        } catch (ClassNotFoundException e) {
+            // Not java 9+
+        }
+        SUPPORTED_SSE_SINK_TYPES = Collections.unmodifiableSet(set);
+    }
+
+    public static boolean isSseSinkParam(Class<?> type) {
+        return SUPPORTED_SSE_SINK_TYPES.contains(type);
+    }
+}
diff --git a/media/sse/src/main/java/org/glassfish/jersey/media/sse/internal/SseEventSinkValueParamProvider.java b/media/sse/src/main/java/org/glassfish/jersey/media/sse/internal/SseEventSinkValueParamProvider.java
index ed76f58a3a5..9bd85bd169f 100644
--- a/media/sse/src/main/java/org/glassfish/jersey/media/sse/internal/SseEventSinkValueParamProvider.java
+++ b/media/sse/src/main/java/org/glassfish/jersey/media/sse/internal/SseEventSinkValueParamProvider.java
@@ -24,12 +24,12 @@
 import javax.inject.Inject;
 import javax.inject.Provider;
 
-import org.glassfish.jersey.internal.jsr166.JerseyFlowSubscriber;
 import org.glassfish.jersey.server.AsyncContext;
 import org.glassfish.jersey.server.ContainerRequest;
 import org.glassfish.jersey.server.internal.inject.AbstractValueParamProvider;
 import org.glassfish.jersey.server.internal.inject.MultivaluedParameterExtractorProvider;
 import org.glassfish.jersey.server.model.Parameter;
+import org.glassfish.jersey.server.model.internal.SseTypeResolver;
 import org.glassfish.jersey.server.spi.internal.ValueParamProvider;
 
 /**
@@ -60,7 +60,7 @@ protected Function<ContainerRequest, SseEventSink> createValueProvider(Parameter
         }
 
         final Class<?> rawParameterType = parameter.getRawType();
-        if ((JerseyFlowSubscriber.isSubscriber(rawParameterType) || rawParameterType == SseEventSink.class)
+        if (SseTypeResolver.isSseSinkParam(rawParameterType)
                 && parameter.isAnnotationPresent(Context.class)) {
             return new SseEventSinkValueSupplier(asyncContextSupplier);
         }