diff --git a/spring-core/src/main/java/org/springframework/util/LinkedCaseInsensitiveMap.java b/spring-core/src/main/java/org/springframework/util/LinkedCaseInsensitiveMap.java
index b221ca9a265..0a2da8c73f0 100644
--- a/spring-core/src/main/java/org/springframework/util/LinkedCaseInsensitiveMap.java
+++ b/spring-core/src/main/java/org/springframework/util/LinkedCaseInsensitiveMap.java
@@ -222,17 +222,22 @@ public class LinkedCaseInsensitiveMap<V extends @Nullable Object> implements Map
 
 	@Override
 	public @Nullable V computeIfAbsent(String key, Function<? super String, ? extends V> mappingFunction) {
-		String oldKey = this.caseInsensitiveKeys.putIfAbsent(convertKey(key), key);
+		String convertedKey = convertKey(key);
+		String oldKey = this.caseInsensitiveKeys.get(convertedKey);
 		if (oldKey != null) {
 			V oldKeyValue = this.targetMap.get(oldKey);
 			if (oldKeyValue != null) {
 				return oldKeyValue;
 			}
-			else {
-				key = oldKey;
-			}
+			return this.targetMap.computeIfAbsent(oldKey, mappingFunction);
 		}
-		return this.targetMap.computeIfAbsent(key, mappingFunction);
+		return this.targetMap.computeIfAbsent(key, k -> {
+			V value = mappingFunction.apply(k);
+			if (value != null) {
+				this.caseInsensitiveKeys.putIfAbsent(convertedKey, k);
+			}
+			return value;
+		});
 	}
 
 	@Override
diff --git a/spring-core/src/test/java/org/springframework/util/LinkedCaseInsensitiveMapTests.java b/spring-core/src/test/java/org/springframework/util/LinkedCaseInsensitiveMapTests.java
index 43840c6168d..6b7e1a86f04 100644
--- a/spring-core/src/test/java/org/springframework/util/LinkedCaseInsensitiveMapTests.java
+++ b/spring-core/src/test/java/org/springframework/util/LinkedCaseInsensitiveMapTests.java
@@ -22,6 +22,7 @@ import java.util.Map;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link LinkedCaseInsensitiveMap}.
@@ -106,6 +107,7 @@ class LinkedCaseInsensitiveMapTests {
 		assertThat(map.put("null", null)).isEqualTo("value");
 		assertThat(map.computeIfAbsent("NULL", s -> "value")).isEqualTo("value");
 		assertThat(map.get("null")).isEqualTo("value");
+		assertThat(map.keySet()).containsExactly("Key", "null");
 	}
 
 	@Test
@@ -115,6 +117,50 @@ class LinkedCaseInsensitiveMapTests {
 		assertThat(map.computeIfAbsent("Key", key -> "value3")).isEqualTo("value1");
 	}
 
+	@Test
+	void computeIfAbsentWithNullComputedValue() {
+		assertThat(map.computeIfAbsent("Key", key -> null)).isNull();
+		assertThat(map).isEmpty();
+		assertThat(map.containsKey("key")).isFalse();
+	}
+
+	@Test
+	void computeIfAbsentAfterNullComputedValueUsesGivenKey() {
+		assertThat(map.computeIfAbsent("Key", key -> null)).isNull();
+		assertThat(map.computeIfAbsent("KEY", key -> "value")).isEqualTo("value");
+		assertThat(map.keySet()).containsExactly("KEY");
+	}
+
+	@Test
+	void computeIfAbsentWithFailingMappingFunction() {
+		assertThatIllegalStateException().isThrownBy(() ->
+				map.computeIfAbsent("Key", key -> { throw new IllegalStateException(); }));
+		assertThat(map).isEmpty();
+		assertThat(map.containsKey("key")).isFalse();
+	}
+
+	@Test
+	void computeIfAbsentWithNullComputedValueForExistingNullValue() {
+		assertThat(map.put("Key", null)).isNull();
+		assertThat(map.computeIfAbsent("KEY", key -> null)).isNull();
+		assertThat(map).hasSize(1);
+		assertThat(map.containsKey("key")).isTrue();
+		assertThat(map.keySet()).containsExactly("Key");
+	}
+
+	@Test
+	void computeIfAbsentWithImmediatelyEvictedEntry() {
+		LinkedCaseInsensitiveMap<String> evictingMap = new LinkedCaseInsensitiveMap<>() {
+			@Override
+			protected boolean removeEldestEntry(Map.Entry<String, String> eldest) {
+				return true;
+			}
+		};
+		assertThat(evictingMap.computeIfAbsent("Key", key -> "value")).isEqualTo("value");
+		assertThat(evictingMap).isEmpty();
+		assertThat(evictingMap.containsKey("key")).isFalse();
+	}
+
 	@Test
 	void mapClone() {
 		assertThat(map.put("key", "value1")).isNull();