diff --git a/Xcodes/Backend/AppState.swift b/Xcodes/Backend/AppState.swift
index da38798..ff163a8 100644
--- a/Xcodes/Backend/AppState.swift
+++ b/Xcodes/Backend/AppState.swift
@@ -450,6 +450,9 @@ class AppState: ObservableObject {
         // Map all of the available versions into Xcode values that join available and installed Xcode data for display.
         var newAllXcodes = adjustedAvailableXcodes
             .filter { availableXcode in
+                // If we don't have the build identifier, don't attempt to filter prerelease versions with identical build identifiers
+                guard !availableXcode.version.buildMetadataIdentifiers.isEmpty else { return true }
+
                 let availableXcodesWithIdenticalBuildIdentifiers = availableXcodes
                     .filter({ $0.version.buildMetadataIdentifiers == availableXcode.version.buildMetadataIdentifiers })
                 
@@ -466,7 +469,10 @@ class AppState: ObservableObject {
                 let identicalBuilds: [Version]
                 let prereleaseAvailableXcodesWithIdenticalBuildIdentifiers = availableXcodes
                     .filter {
-                        $0.version.buildMetadataIdentifiers == availableXcode.version.buildMetadataIdentifiers && !$0.version.prereleaseIdentifiers.isEmpty
+                        return $0.version.buildMetadataIdentifiers == availableXcode.version.buildMetadataIdentifiers &&
+                            !$0.version.prereleaseIdentifiers.isEmpty &&
+                            // If we don't have the build identifier, don't consider this as a potential identical build
+                            !$0.version.buildMetadataIdentifiers.isEmpty
                     }
                 // If this is the release version, add the identical builds to it
                 if !prereleaseAvailableXcodesWithIdenticalBuildIdentifiers.isEmpty, availableXcode.version.prereleaseIdentifiers.isEmpty {
diff --git a/XcodesTests/AppStateUpdateTests.swift b/XcodesTests/AppStateUpdateTests.swift
index 616e460..39d0d21 100644
--- a/XcodesTests/AppStateUpdateTests.swift
+++ b/XcodesTests/AppStateUpdateTests.swift
@@ -232,4 +232,30 @@ class AppStateUpdateTests: XCTestCase {
         XCTAssertEqual(subject.allXcodes.map(\.version), [Version("12.4.0+12D4e")!])
         XCTAssertEqual(subject.allXcodes.map(\.identicalBuilds), [[Version("12.4.0+12D4e")!, Version("12.4.0-RC+12D4e")!]])
     }
+    
+    func testIdenticalBuilds_AppleDataSource_DoNotMergeVersionsWithoutBuildIdentifiers() {
+        Current.defaults.string = { key in
+            if key == "dataSource" {
+                return "apple" 
+            } else {
+                return nil
+            }
+        }
+
+        subject.allXcodes = [
+        ]
+        
+        subject.updateAllXcodes(
+            availableXcodes: [
+                AvailableXcode(version: Version("12.4.0")!, url: URL(string: "https://apple.com/xcode.xip")!, filename: "mock.xip", releaseDate: nil),
+                AvailableXcode(version: Version("12.3.0-RC")!, url: URL(string: "https://apple.com/xcode.xip")!, filename: "mock.xip", releaseDate: nil),
+            ], 
+            installedXcodes: [
+            ], 
+            selectedXcodePath: nil
+        )
+        
+        XCTAssertEqual(subject.allXcodes.map(\.version), [Version("12.4.0")!, Version("12.3.0-RC")!])
+        XCTAssertEqual(subject.allXcodes.map(\.identicalBuilds), [[], []])
+    }
 }