diff --git a/docs/test_cases/t00014.md b/docs/test_cases/t00014.md
index 471189bd..adec4d43 100644
--- a/docs/test_cases/t00014.md
+++ b/docs/test_cases/t00014.md
@@ -13,11 +13,16 @@ diagrams:
     include:
       namespaces:
         - clanguml::t00014
+    exclude:
+      namespaces:
+        - std
+        - clanguml::t00014::std
 
 ```
 ## Source code
 ```cpp
 #include <algorithm>
+#include <functional>
 #include <ios>
 #include <map>
 #include <numeric>
@@ -46,6 +51,9 @@ template <typename T, typename P> struct A {
 
 template <typename T> using AString = A<T, std::string>;
 
+template <typename... T> using GeneralCallback = std::function<void(T..., int)>;
+using VoidCallback = GeneralCallback<>;
+
 struct B {
     std::string value;
 };
@@ -65,6 +73,8 @@ class R {
     AStringString stringstring;
     BVector bs;
     BVector2 bs2;
+    GeneralCallback<AIntString> cb;
+    VoidCallback vcb;
 };
 }
 }
diff --git a/docs/test_cases/t00014_class.png b/docs/test_cases/t00014_class.png
index 12ffc9e8..c0d9b9db 100644
Binary files a/docs/test_cases/t00014_class.png and b/docs/test_cases/t00014_class.png differ
diff --git a/docs/test_cases/t00015_class.png b/docs/test_cases/t00015_class.png
index 06c5af8c..e6f9ed2c 100644
Binary files a/docs/test_cases/t00015_class.png and b/docs/test_cases/t00015_class.png differ
diff --git a/docs/test_cases/t00016_class.png b/docs/test_cases/t00016_class.png
index 2fb91e5e..9e82fe13 100644
Binary files a/docs/test_cases/t00016_class.png and b/docs/test_cases/t00016_class.png differ
diff --git a/src/config/config.h b/src/config/config.h
index 978e2f6c..06866cf6 100644
--- a/src/config/config.h
+++ b/src/config/config.h
@@ -111,8 +111,10 @@ struct diagram {
         auto name = clanguml::util::unqualify(name_);
 
         for (const auto &ex : exclude.namespaces) {
-            if (name.find(ex) == 0)
+            if (name.find(ex) == 0) {
+                spdlog::debug("Skipping from diagram: {}", name);
                 return false;
+            }
         }
 
         // If no inclusive namespaces are provided,
diff --git a/src/puml/class_diagram_generator.h b/src/puml/class_diagram_generator.h
index d00a1ea3..1ed6a9e8 100644
--- a/src/puml/class_diagram_generator.h
+++ b/src/puml/class_diagram_generator.h
@@ -341,16 +341,24 @@ public:
 
         if (m_config.should_include_entities("classes")) {
             for (const auto &c : m_model.classes) {
+                if (!c.is_template_instantiation &&
+                    !m_config.should_include(c.name))
+                    continue;
                 generate_alias(c, ostr);
                 ostr << std::endl;
             }
 
             for (const auto &e : m_model.enums) {
+                if (!m_config.should_include(e.name))
+                    continue;
                 generate_alias(e, ostr);
                 ostr << std::endl;
             }
 
             for (const auto &c : m_model.classes) {
+                if (!c.is_template_instantiation &&
+                    !m_config.should_include(c.name))
+                    continue;
                 generate(c, ostr);
                 ostr << std::endl;
             }
diff --git a/src/uml/class_diagram_visitor.cc b/src/uml/class_diagram_visitor.cc
index 2bade83c..8b26f103 100644
--- a/src/uml/class_diagram_visitor.cc
+++ b/src/uml/class_diagram_visitor.cc
@@ -1048,31 +1048,40 @@ void tu_visitor::find_relationships(const cppast::cpp_type &t_,
 class_ tu_visitor::build_template_instantiation(
     const cppast::cpp_template_instantiation_type &t)
 {
-    const auto &primary_template_ref =
-        static_cast<const cppast::cpp_class_template &>(
-            t.primary_template().get(ctx.entity_index)[0].get())
-            .class_();
-
-    auto full_template_name =
-        cx::util::full_name(ctx.namespace_, primary_template_ref);
-
-    LOG_DBG("Found template instantiation: {} ({}) ..|> {}, {}",
-        cppast::to_string(t), cppast::to_string(t.canonical()),
-        t.primary_template().name(), full_template_name);
-
     class_ tinst;
+    std::string full_template_name;
 
-    if (full_template_name.back() == ':')
-        tinst.name = full_template_name + tinst.name;
+    if (t.primary_template().get(ctx.entity_index).size()) {
+        const auto &primary_template_ref =
+            static_cast<const cppast::cpp_class_template &>(
+                t.primary_template().get(ctx.entity_index)[0].get())
+                .class_();
 
-    if (primary_template_ref.user_data()) {
-        tinst.base_template_usr =
-            static_cast<const char *>(primary_template_ref.user_data());
-        LOG_DBG("Primary template ref set to: {}", tinst.base_template_usr);
+        full_template_name =
+            cx::util::full_name(ctx.namespace_, primary_template_ref);
+
+        LOG_DBG("Found template instantiation: {} ({}) ..|> {}, {}",
+            cppast::to_string(t), cppast::to_string(t.canonical()),
+            t.primary_template().name(), full_template_name);
+
+        if (full_template_name.back() == ':')
+            tinst.name = full_template_name + tinst.name;
+
+        if (primary_template_ref.user_data()) {
+            tinst.base_template_usr =
+                static_cast<const char *>(primary_template_ref.user_data());
+            LOG_DBG("Primary template ref set to: {}", tinst.base_template_usr);
+        }
+        else
+            LOG_WARN("No user data for base template {}",
+                primary_template_ref.name());
+    }
+    else {
+        LOG_WARN("Template instantiation {} has no primary template",
+            cppast::to_string(t));
+
+        full_template_name = cppast::to_string(t);
     }
-    else
-        LOG_WARN(
-            "No user data for base template {}", primary_template_ref.name());
 
     // Extract namespace from base template name
     auto ns_toks = clanguml::util::split(
diff --git a/tests/t00014/.clanguml b/tests/t00014/.clanguml
index b6e5b791..2534f83f 100644
--- a/tests/t00014/.clanguml
+++ b/tests/t00014/.clanguml
@@ -10,3 +10,7 @@ diagrams:
     include:
       namespaces:
         - clanguml::t00014
+    exclude:
+      namespaces:
+        - std
+        - clanguml::t00014::std
diff --git a/tests/t00014/t00014.cc b/tests/t00014/t00014.cc
index 45460849..1f84ed26 100644
--- a/tests/t00014/t00014.cc
+++ b/tests/t00014/t00014.cc
@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <functional>
 #include <ios>
 #include <map>
 #include <numeric>
@@ -27,6 +28,9 @@ template <typename T, typename P> struct A {
 
 template <typename T> using AString = A<T, std::string>;
 
+template <typename... T> using GeneralCallback = std::function<void(T..., int)>;
+using VoidCallback = GeneralCallback<>;
+
 struct B {
     std::string value;
 };
@@ -46,6 +50,8 @@ class R {
     AStringString stringstring;
     BVector bs;
     BVector2 bs2;
+    GeneralCallback<AIntString> cb;
+    VoidCallback vcb;
 };
 }
 }
diff --git a/tests/t00014/test_case.h b/tests/t00014/test_case.h
index 1f82924e..1bf5ceef 100644
--- a/tests/t00014/test_case.h
+++ b/tests/t00014/test_case.h
@@ -1,5 +1,5 @@
 /**
- * tests/t00014/test_case.cc
+ * tests/t00014/test_case.h
  *
  * Copyright (c) 2021 Bartek Kryza <bkryza@gmail.com>
  *
@@ -27,7 +27,7 @@ TEST_CASE("t00014", "[test-case][class]")
     REQUIRE_THAT(diagram->include.namespaces,
         VectorContains(std::string{"clanguml::t00014"}));
 
-    REQUIRE(diagram->exclude.namespaces.size() == 0);
+    REQUIRE(diagram->exclude.namespaces.size() == 2);
 
     REQUIRE(diagram->should_include("clanguml::t00014::S"));
 
@@ -46,9 +46,6 @@ TEST_CASE("t00014", "[test-case][class]")
     REQUIRE_THAT(puml, IsClassTemplate("AString", "float"));
 
     REQUIRE_THAT(puml, IsInstantiation(_A("A<T,P>"), _A("A<T,std::string>")));
-    // TODO
-    // REQUIRE_THAT(puml, IsInstantiation(_A("A<T,std::string>"),
-    // _A("A<bool,std::string>")));
     REQUIRE_THAT(
         puml, IsInstantiation(_A("A<T,std::string>"), _A("AString<float>")));
     REQUIRE_THAT(