diff --git a/src/main/java/org/springframework/data/convert/CustomConversions.java b/src/main/java/org/springframework/data/convert/CustomConversions.java
index 25023bffc..2321e9b9e 100644
--- a/src/main/java/org/springframework/data/convert/CustomConversions.java
+++ b/src/main/java/org/springframework/data/convert/CustomConversions.java
@@ -393,7 +393,10 @@ public class CustomConversions {
 		public Class<?> computeIfAbsent(Class<?> sourceType, Class<?> targetType,
 				Function<ConvertiblePair, Class<?>> mappingFunction) {
 
-			TargetTypes targetTypes = customReadTargetTypes.computeIfAbsent(sourceType, TargetTypes::new);
+			TargetTypes targetTypes = customReadTargetTypes.get(sourceType);
+			if (targetTypes == null) {
+				targetTypes = customReadTargetTypes.computeIfAbsent(sourceType, TargetTypes::new);
+			}
 			return targetTypes.computeIfAbsent(targetType, mappingFunction);
 		}
 
diff --git a/src/main/java/org/springframework/data/convert/DefaultTypeMapper.java b/src/main/java/org/springframework/data/convert/DefaultTypeMapper.java
index 2a59aea09..8065323ff 100644
--- a/src/main/java/org/springframework/data/convert/DefaultTypeMapper.java
+++ b/src/main/java/org/springframework/data/convert/DefaultTypeMapper.java
@@ -127,7 +127,14 @@ public class DefaultTypeMapper<S> implements TypeMapper<S> {
 	 */
 	@Nullable
 	private TypeInformation<?> getFromCacheOrCreate(Alias alias) {
-		return typeCache.computeIfAbsent(alias, getAlias).orElse(null);
+
+		Optional<TypeInformation<?>> typeInformation = typeCache.get(alias);
+
+		if (typeInformation == null) {
+			typeInformation = typeCache.computeIfAbsent(alias, getAlias);
+		}
+
+		return typeInformation.orElse(null);
 	}
 
 	/*