diff --git a/python/templates/Collection.cc.jinja2 b/python/templates/Collection.cc.jinja2
index b7c49cdab..4828750a9 100644
--- a/python/templates/Collection.cc.jinja2
+++ b/python/templates/Collection.cc.jinja2
@@ -13,6 +13,10 @@
 {{ include }}
 {% endfor %}
 
+#if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
+#include "nlohmann/json.hpp"
+#endif
+
 // standard includes
 #include <stdexcept>
 #include <iomanip>
diff --git a/python/templates/Collection.h.jinja2 b/python/templates/Collection.h.jinja2
index 0e49aec53..616e1bfc8 100644
--- a/python/templates/Collection.h.jinja2
+++ b/python/templates/Collection.h.jinja2
@@ -19,7 +19,7 @@
 #include "podio/CollectionIDTable.h"
 
 #if defined(PODIO_JSON_OUTPUT) && !defined(__CLING__)
-#include "nlohmann/json.hpp"
+#include "nlohmann/json_fwd.hpp"
 #endif
 
 #include <string>
diff --git a/python/templates/MutableObject.cc.jinja2 b/python/templates/MutableObject.cc.jinja2
index 9ed099278..edbca8da9 100644
--- a/python/templates/MutableObject.cc.jinja2
+++ b/python/templates/MutableObject.cc.jinja2
@@ -8,6 +8,10 @@
 {{ include }}
 {% endfor %}
 
+#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#include "nlohmann/json.hpp"
+#endif
+
 #include <ostream>
 
 {{ utils.namespace_open(class.namespace) }}
diff --git a/python/templates/MutableObject.h.jinja2 b/python/templates/MutableObject.h.jinja2
index ebdac4f53..b669a2b80 100644
--- a/python/templates/MutableObject.h.jinja2
+++ b/python/templates/MutableObject.h.jinja2
@@ -17,7 +17,7 @@
 #include <cstddef>
 
 #ifdef PODIO_JSON_OUTPUT
-#include "nlohmann/json.hpp"
+#include "nlohmann/json_fwd.hpp"
 #endif
 
 {{ utils.forward_decls(forward_declarations) }}
diff --git a/python/templates/Object.cc.jinja2 b/python/templates/Object.cc.jinja2
index 0d4b07b7e..37414ec52 100644
--- a/python/templates/Object.cc.jinja2
+++ b/python/templates/Object.cc.jinja2
@@ -8,6 +8,10 @@
 {{ include }}
 {% endfor %}
 
+#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#include "nlohmann/json.hpp"
+#endif
+
 #include <ostream>
 
 {{ utils.namespace_open(class.namespace) }}
diff --git a/python/templates/Object.h.jinja2 b/python/templates/Object.h.jinja2
index 42d737cb5..bec9fc0da 100644
--- a/python/templates/Object.h.jinja2
+++ b/python/templates/Object.h.jinja2
@@ -14,8 +14,8 @@
 #include <ostream>
 #include <cstddef>
 
-#ifdef PODIO_JSON_OUTPUT
-#include "nlohmann/json.hpp"
+#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
+#include "nlohmann/json_fwd.hpp"
 #endif
 
 {{ utils.forward_decls(forward_declarations) }}
diff --git a/python/templates/macros/declarations.jinja2 b/python/templates/macros/declarations.jinja2
index af46f499e..a0c976bc4 100644
--- a/python/templates/macros/declarations.jinja2
+++ b/python/templates/macros/declarations.jinja2
@@ -134,7 +134,7 @@
 {%- endmacro %}
 
 {% macro json_output(type, prefix='') %}
-#ifdef PODIO_JSON_OUTPUT
+#ifdef PODIO_JSON_OUTPUT && !defined(__CLING__)
 void to_json(nlohmann::json& j, const {{ prefix }}{{ type }}& value);
 #endif
 {% endmacro %}