diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
index 99674edc4f5f7a..98022b05565fa5 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
@@ -707,7 +707,7 @@ public Label getPropellerOptimizeLabel() {
 
   @Option(
       name = "experimental_inmemory_dotd_files",
-      defaultValue = "false",
+      defaultValue = "true",
       documentationCategory = OptionDocumentationCategory.BUILD_TIME_OPTIMIZATION,
       effectTags = {
         OptionEffectTag.LOADING_AND_ANALYSIS,