diff --git a/core/runtime/src/main/java/io/quarkus/logging/Log.java b/core/runtime/src/main/java/io/quarkus/logging/Log.java
index 135b391c2f79c..3f4f3472e2739 100644
--- a/core/runtime/src/main/java/io/quarkus/logging/Log.java
+++ b/core/runtime/src/main/java/io/quarkus/logging/Log.java
@@ -2,6 +2,8 @@
 
 import org.jboss.logging.Logger;
 
+import io.quarkus.runtime.Application;
+
 // automatically generated by io.quarkus.logging.GenerateLog
 /**
  * Copy of {@link org.jboss.logging.BasicLogger}.
@@ -12,14 +14,18 @@ public final class Log {
 
     private static final StackWalker stackWalker = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE);
 
-    private static final boolean shouldFail = !isTest();
+    private static final boolean shouldFail = shouldFail();
 
-    private static boolean isTest() {
+    private static boolean shouldFail() {
+        // inside Quarkus, all call sites should be rewritten
+        if (Application.currentApplication() != null)
+            return true;
+        // outside Quarkus, allow in tests
         try {
             Class.forName("org.junit.jupiter.api.Assertions");
-            return true;
-        } catch (java.lang.ClassNotFoundException ignored) {
             return false;
+        } catch (java.lang.ClassNotFoundException ignored) {
+            return true;
         }
     }
 
@@ -2919,6 +2925,6 @@ public static void logf(String loggerFqcn, Logger.Level level, Throwable t, Stri
 
     private static UnsupportedOperationException fail() {
         return new UnsupportedOperationException(
-                "Using io.quarkus.logging.Log is only possible with Quarkus bytecode transformation");
+                "Using io.quarkus.logging.Log is only possible with Quarkus bytecode transformation; make sure the archive is indexed, for example by including a beans.xml file");
     }
 }
diff --git a/core/runtime/src/test/java/io/quarkus/logging/GenerateLog.java b/core/runtime/src/test/java/io/quarkus/logging/GenerateLog.java
index b108f58de3d38..b46335055ca64 100644
--- a/core/runtime/src/test/java/io/quarkus/logging/GenerateLog.java
+++ b/core/runtime/src/test/java/io/quarkus/logging/GenerateLog.java
@@ -29,10 +29,14 @@
 import com.github.javaparser.ast.nodeTypes.NodeWithSimpleName;
 import com.github.javaparser.ast.stmt.BlockStmt;
 import com.github.javaparser.ast.stmt.CatchClause;
+import com.github.javaparser.ast.stmt.IfStmt;
 import com.github.javaparser.ast.stmt.ReturnStmt;
+import com.github.javaparser.ast.stmt.Statement;
 import com.github.javaparser.ast.stmt.TryStmt;
 import com.github.javaparser.ast.type.PrimitiveType;
 
+import io.quarkus.runtime.Application;
+
 public class GenerateLog {
     private static final String CLASS_JAVADOC = "" +
             "Copy of {@link org.jboss.logging.BasicLogger}.\n" +
@@ -69,6 +73,7 @@ private static void generateLogClass(String templateSource) {
         CompilationUnit unit = new CompilationUnit();
         unit.setPackageDeclaration("io.quarkus.logging");
         unit.addImport(Logger.class);
+        unit.addImport(Application.class);
         unit.addOrphanComment(new LineComment(" automatically generated by io.quarkus.logging.GenerateLog"));
 
         ClassOrInterfaceDeclaration clazz = unit.addClass("Log", Modifier.Keyword.PUBLIC, Modifier.Keyword.FINAL)
@@ -79,26 +84,33 @@ private static void generateLogClass(String templateSource) {
                 Modifier.Keyword.PRIVATE, Modifier.Keyword.STATIC, Modifier.Keyword.FINAL);
 
         clazz.addFieldWithInitializer(PrimitiveType.booleanType(), "shouldFail",
-                StaticJavaParser.parseExpression("!isTest()"),
+                StaticJavaParser.parseExpression("shouldFail()"),
                 Modifier.Keyword.PRIVATE, Modifier.Keyword.STATIC, Modifier.Keyword.FINAL);
 
         {
-            MethodDeclaration method = clazz.addMethod("isTest");
+            MethodDeclaration method = clazz.addMethod("shouldFail");
             method.setPrivate(true);
             method.setStatic(true);
             method.setType(PrimitiveType.booleanType());
             BlockStmt body = new BlockStmt();
 
+            Expression ifCondition = StaticJavaParser.parseExpression("Application.currentApplication() != null");
+            Statement thenPart = StaticJavaParser.parseStatement("return true;");
+
+            body.addOrphanComment(new LineComment(" inside Quarkus, all call sites should be rewritten"));
+            body.addStatement(new IfStmt(ifCondition, thenPart, null));
+
             BlockStmt tryPart = new BlockStmt();
             tryPart.addStatement("Class.forName(\"org.junit.jupiter.api.Assertions\");");
-            tryPart.addStatement("return true;");
+            tryPart.addStatement("return false;");
 
             BlockStmt catchPart = new BlockStmt();
-            catchPart.addStatement("return false;");
+            catchPart.addStatement("return true;");
             CatchClause catchClause = new CatchClause(
                     new Parameter(StaticJavaParser.parseType(ClassNotFoundException.class.getName()), "ignored"),
                     catchPart);
 
+            body.addOrphanComment(new LineComment(" outside Quarkus, allow in tests"));
             body.addStatement(new TryStmt(tryPart, new NodeList<>(catchClause), null));
             method.setBody(body);
         }
@@ -133,7 +145,8 @@ private static void generateLogClass(String templateSource) {
             method.setType(UnsupportedOperationException.class);
             BlockStmt body = new BlockStmt();
             body.addStatement("return new UnsupportedOperationException(\"Using " + Log.class.getName()
-                    + " is only possible with Quarkus bytecode transformation\");");
+                    + " is only possible with Quarkus bytecode transformation;"
+                    + " make sure the archive is indexed, for example by including a beans.xml file\");");
             method.setBody(body);
         }
 
diff --git a/core/runtime/src/test/java/io/quarkus/logging/LoggingApiCompletenessTest.java b/core/runtime/src/test/java/io/quarkus/logging/LoggingApiCompletenessTest.java
index 33673ab52f9c0..8904b356fe290 100644
--- a/core/runtime/src/test/java/io/quarkus/logging/LoggingApiCompletenessTest.java
+++ b/core/runtime/src/test/java/io/quarkus/logging/LoggingApiCompletenessTest.java
@@ -62,7 +62,7 @@ public void compareWithJbossLogging() {
     private static boolean isPrivateStaticAdditionalMethod(Method method) {
         return Modifier.isPrivate(method.getModifiers())
                 && Modifier.isStatic(method.getModifiers())
-                && ("fail".equals(method.getName()) || "isTest".equals(method.getName()));
+                && ("fail".equals(method.getName()) || "shouldFail".equals(method.getName()));
     }
 
     private static boolean areEquivalent(Method jbossLoggingMethod, Method quarkusLogMethod) {