diff --git a/Package.resolved b/Package.resolved
index 7b6e6951..9102edb5 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,5 +1,5 @@
 {
-  "originHash" : "b1e7fc8e75fb3f86eed27972a51c665f7e6482f3058b105c91aee6e1ad0b8018",
+  "originHash" : "073a03e2259fb84a5096d6021fa10f50c991ddb0c1c292921363371342a4a294",
   "pins" : [
     {
       "identity" : "combine-schedulers",
@@ -10,15 +10,6 @@
         "version" : "1.0.3"
       }
     },
-    {
-      "identity" : "swift-case-paths",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/pointfreeco/swift-case-paths",
-      "state" : {
-        "revision" : "6989976265be3f8d2b5802c722f9ba168e227c71",
-        "version" : "1.7.2"
-      }
-    },
     {
       "identity" : "swift-clocks",
       "kind" : "remoteSourceControl",
@@ -100,15 +91,6 @@
         "version" : "602.0.0"
       }
     },
-    {
-      "identity" : "swift-tagged",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/pointfreeco/swift-tagged",
-      "state" : {
-        "revision" : "3907a9438f5b57d317001dc99f3f11b46882272b",
-        "version" : "0.10.0"
-      }
-    },
     {
       "identity" : "xctest-dynamic-overlay",
       "kind" : "remoteSourceControl",
diff --git a/Sources/StructuredQueriesCore/Optional.swift b/Sources/StructuredQueriesCore/Optional.swift
index 0788504a..fa0c9c3b 100644
--- a/Sources/StructuredQueriesCore/Optional.swift
+++ b/Sources/StructuredQueriesCore/Optional.swift
@@ -275,7 +275,9 @@ extension QueryExpression where QueryValue: _OptionalProtocol {
   public func map<T>(
     _ transform: (SQLQueryExpression<QueryValue.Wrapped>) -> some QueryExpression<T>
   ) -> some QueryExpression<T?> {
-    SQLQueryExpression(transform(SQLQueryExpression(queryFragment)).queryFragment)
+    Case(SQLQueryExpression("\(self) IS NULL"))
+      .when(SQLQueryExpression("1"), then: SQLQueryExpression("NULL"))
+      .else(SQLQueryExpression(transform(SQLQueryExpression(queryFragment)).queryFragment))
   }
 
   /// Creates a new optional expression from this one by applying an unwrapped version of this
diff --git a/Tests/StructuredQueriesTests/MapTests.swift b/Tests/StructuredQueriesTests/MapTests.swift
new file mode 100644
index 00000000..5e2242a4
--- /dev/null
+++ b/Tests/StructuredQueriesTests/MapTests.swift
@@ -0,0 +1,54 @@
+import Dependencies
+import Foundation
+import InlineSnapshotTesting
+import SQLite3
+import StructuredQueries
+import StructuredQueriesSQLite
+import StructuredQueriesTestSupport
+import Testing
+import _StructuredQueriesSQLite
+
+extension SnapshotTests {
+  @Suite struct MapTests {
+    @Dependency(\.defaultDatabase) var database
+
+    @Test func mapWithDatabaseFunction() throws {
+      $increment.install(database.handle)
+      try database.execute("""
+        CREATE TABLE "optionalIntegers" (
+          "value" INTEGER
+        ) STRICT
+        """)
+      try database.execute("""
+        INSERT INTO "optionalIntegers" ("value") VALUES (1), (NULL), (3)
+        """)
+
+      assertQuery(
+        OptionalInteger.select {
+          $0.value.map { $increment($0) }
+        }
+      ) {
+        """
+        SELECT CASE "optionalIntegers"."value" IS NULL WHEN 1 THEN NULL ELSE "increment"("optionalIntegers"."value") END
+        FROM "optionalIntegers"
+        """
+      } results: {
+        """
+        ┌─────┐
+        │ 2   │
+        │ nil │
+        │ 4   │
+        └─────┘
+        """
+      }
+    }
+  }
+}
+
+@Table struct OptionalInteger {
+  let value: Int?
+}
+@DatabaseFunction(isDeterministic: true)
+private func increment(_ value: Int) -> Int {
+  value + 1
+}
diff --git a/Tests/StructuredQueriesTests/SelectTests.swift b/Tests/StructuredQueriesTests/SelectTests.swift
index 626ae77c..da0f5146 100644
--- a/Tests/StructuredQueriesTests/SelectTests.swift
+++ b/Tests/StructuredQueriesTests/SelectTests.swift
@@ -1369,7 +1369,7 @@ extension SnapshotTests {
         }
         assertQuery(query) {
           """
-          SELECT ("reminders"."priority") < (3)
+          SELECT CASE "reminders"."priority" IS NULL WHEN 1 THEN NULL ELSE ("reminders"."priority") < (3) END
           FROM "reminders"
           """
         } results: {