diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 2a5af40..c12e3b2 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -30,8 +30,7 @@
 namespace android {
 namespace fs_mgr {
 
-bool MetadataBuilder::sABOverrideSet;
-bool MetadataBuilder::sABOverrideValue;
+std::optional<bool> MetadataBuilder::sABOverride;
 std::optional<bool> MetadataBuilder::sRetrofitDap;
 
 static const std::string kDefaultGroup = "default";
@@ -212,8 +211,7 @@
 }
 
 void MetadataBuilder::OverrideABForTesting(bool ab_device) {
-    sABOverrideSet = true;
-    sABOverrideValue = ab_device;
+    sABOverride = ab_device;
 }
 
 void MetadataBuilder::OverrideRetrofitDynamicParititonsForTesting(bool retrofit) {
@@ -1051,9 +1049,9 @@
     auto_slot_suffixing_ = true;
 }
 
-bool MetadataBuilder::IsABDevice() const {
-    if (sABOverrideSet) {
-        return sABOverrideValue;
+bool MetadataBuilder::IsABDevice() {
+    if (sABOverride.has_value()) {
+        return *sABOverride;
     }
     return !android::base::GetProperty("ro.boot.slot_suffix", "").empty();
 }
diff --git a/fs_mgr/liblp/include/liblp/builder.h b/fs_mgr/liblp/include/liblp/builder.h
index 55d82b1..a2221ef 100644
--- a/fs_mgr/liblp/include/liblp/builder.h
+++ b/fs_mgr/liblp/include/liblp/builder.h
@@ -309,7 +309,9 @@
     void ImportExtents(Partition* dest, const LpMetadata& metadata,
                        const LpMetadataPartition& source);
     bool ImportPartition(const LpMetadata& metadata, const LpMetadataPartition& source);
-    bool IsABDevice() const;
+
+    // Return true if the device is an AB device.
+    static bool IsABDevice();
 
     // Return true if the device is retrofitting dynamic partitions.
     static bool IsRetrofitDynamicPartitionsDevice();
@@ -345,8 +347,7 @@
                                                     const std::vector<Interval>& free_list,
                                                     uint64_t sectors_needed) const;
 
-    static bool sABOverrideValue;
-    static bool sABOverrideSet;
+    static std::optional<bool> sABOverride;
     static std::optional<bool> sRetrofitDap;
 
     LpMetadataGeometry geometry_;