diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c832612..4acd9a70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### `jsonschema-generator`
 #### Fixed
 - avoid exception when trying to collect supported enum values from raw `Enum` type (i.e., missing type parameter)
+- avoid exception when trying to find type with annotation when given type is `null`
+
+### `jsonschema-module-jackson`
+#### Fixed
+- avoid exception in subtype resolution, when targeting void method
 
 ## [4.36.0] - 2024-07-20
 ### `jsonschema-generator`
diff --git a/jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/TypeContext.java b/jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/TypeContext.java
index d07c2488..e0cdc899 100644
--- a/jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/TypeContext.java
+++ b/jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/TypeContext.java
@@ -392,7 +392,7 @@ public ResolvedType getTypeWithAnnotation(ResolvedType targetType, Class<? exten
      */
     public ResolvedType getTypeConsideringHierarchyMatching(ResolvedType targetType, Predicate<ResolvedType> check) {
         ResolvedType targetSuperType = targetType;
-        do {
+        while (targetSuperType != null) {
             if (check.test(targetSuperType)) {
                 return targetSuperType;
             }
@@ -403,7 +403,7 @@ public ResolvedType getTypeConsideringHierarchyMatching(ResolvedType targetType,
                 return interfaceWithAnnotation.get();
             }
             targetSuperType = targetSuperType.getParentClass();
-        } while (targetSuperType != null);
+        }
         return null;
     }
 
diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/CustomEnumDefinitionProvider.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/CustomEnumDefinitionProvider.java
index c79925ac..2ddbc0f7 100644
--- a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/CustomEnumDefinitionProvider.java
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/CustomEnumDefinitionProvider.java
@@ -59,6 +59,10 @@ public CustomEnumDefinitionProvider(boolean checkForJsonValueAnnotatedMethod, bo
 
     @Override
     public CustomDefinition provideCustomSchemaDefinition(ResolvedType javaType, SchemaGenerationContext context) {
+        if (javaType == null) {
+            // since 4.37.0: not for void methods
+            return null;
+        }
         Object[] enumConstants = javaType.getErasedType().getEnumConstants();
         if (enumConstants == null || enumConstants.length == 0) {
             return null;
diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonIdentityReferenceDefinitionProvider.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonIdentityReferenceDefinitionProvider.java
index b380cf6c..2c50fe31 100644
--- a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonIdentityReferenceDefinitionProvider.java
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonIdentityReferenceDefinitionProvider.java
@@ -39,6 +39,10 @@ public class JsonIdentityReferenceDefinitionProvider implements CustomDefinition
 
     @Override
     public CustomDefinition provideCustomSchemaDefinition(ResolvedType javaType, SchemaGenerationContext context) {
+        if (javaType == null) {
+            // since 4.37.0: not for void methods
+            return null;
+        }
         return this.getIdentityReferenceType(javaType, context.getTypeContext())
                 .map(context::createDefinitionReference)
                 .map(CustomDefinition::new)
diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonSubTypesResolver.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonSubTypesResolver.java
index e2e04535..aba2eae0 100644
--- a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonSubTypesResolver.java
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonSubTypesResolver.java
@@ -166,6 +166,10 @@ private ResolvedType resolveSubtype(ResolvedType declaredType, JsonSubTypes.Type
      */
     @Override
     public CustomDefinition provideCustomSchemaDefinition(ResolvedType javaType, SchemaGenerationContext context) {
+        if (javaType == null) {
+            // since 4.37.0: not for void methods
+            return null;
+        }
         ResolvedType typeWithTypeInfo = context.getTypeContext().getTypeWithAnnotation(javaType, JsonTypeInfo.class);
         if (typeWithTypeInfo == null || javaType.getErasedType().getAnnotation(JsonSubTypes.class) != null
                 || this.skipSubtypeResolution(javaType, context.getTypeContext())) {
diff --git a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonUnwrappedDefinitionProvider.java b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonUnwrappedDefinitionProvider.java
index 79a6e86c..a825e811 100644
--- a/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonUnwrappedDefinitionProvider.java
+++ b/jsonschema-module-jackson/src/main/java/com/github/victools/jsonschema/module/jackson/JsonUnwrappedDefinitionProvider.java
@@ -43,6 +43,10 @@ public class JsonUnwrappedDefinitionProvider implements CustomDefinitionProvider
 
     @Override
     public CustomDefinition provideCustomSchemaDefinition(ResolvedType javaType, SchemaGenerationContext context) {
+        if (javaType == null) {
+            // since 4.37.0: not for void methods
+            return null;
+        }
         ResolvedTypeWithMembers typeWithMembers = context.getTypeContext().resolveWithMembers(javaType);
 
         if (Arrays.stream(typeWithMembers.getMemberFields()).noneMatch(this::hasJsonUnwrappedAnnotation)