diff --git a/extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/GrpcServerRecorder.java b/extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/GrpcServerRecorder.java
index 54e83ead17432a..8fb4a5db260db3 100644
--- a/extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/GrpcServerRecorder.java
+++ b/extensions/grpc/runtime/src/main/java/io/quarkus/grpc/runtime/GrpcServerRecorder.java
@@ -25,6 +25,8 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.regex.Pattern;
 
+import io.vertx.core.http.HttpServerRequest;
+import io.vertx.core.http.HttpVersion;
 import jakarta.enterprise.inject.Instance;
 
 import org.jboss.logging.Logger;
@@ -216,7 +218,13 @@ public void handle(Void unused) {
 
     // TODO -- handle Avro, plain text ... when supported / needed
     private static boolean isGrpc(RoutingContext rc) {
-        String header = rc.request().getHeader("content-type");
+        HttpServerRequest request = rc.request();
+        HttpVersion version = request.version();
+        if (HttpVersion.HTTP_1_0.equals(version) || HttpVersion.HTTP_1_1.equals(version)) {
+            LOGGER.debugf("Expecting %s, received %s - not a gRPC request", HttpVersion.HTTP_2, version);
+            return false;
+        }
+        String header = request.getHeader("content-type");
         return header != null && GRPC_CONTENT_TYPE.matcher(header.toLowerCase(Locale.ROOT)).matches();
     }