diff --git a/tests/notnull_tests.cpp b/tests/notnull_tests.cpp
index 420c87b..4c317d9 100644
--- a/tests/notnull_tests.cpp
+++ b/tests/notnull_tests.cpp
@@ -441,6 +441,18 @@ TEST(notnull_tests, TestNotNullConstructorTypeDeduction)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+
+        not_null x{&i};
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(not_null{&i});
+#endif
+        helper_const(not_null{&i});
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     {
         int i = 42;
         int* p = &i;
@@ -452,6 +464,19 @@ TEST(notnull_tests, TestNotNullConstructorTypeDeduction)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+        const int* p = &i;
+
+        not_null x{p};
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(not_null{p});
+#endif
+        helper_const(not_null{p});
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     const auto terminateHandler = std::set_terminate([] {
         std::cerr << "Expected Death. TestNotNullConstructorTypeDeduction";
         std::abort();
@@ -503,6 +528,18 @@ TEST(notnull_tests, TestMakeNotNull)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+
+        const auto x = make_not_null(&i);
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(make_not_null(&i));
+#endif
+        helper_const(make_not_null(&i));
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     {
         int i = 42;
         int* p = &i;
@@ -514,6 +551,19 @@ TEST(notnull_tests, TestMakeNotNull)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+        const int* p = &i;
+
+        const auto x = make_not_null(p);
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(make_not_null(p));
+#endif
+        helper_const(make_not_null(p));
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     const auto terminateHandler = std::set_terminate([] {
         std::cerr << "Expected Death. TestMakeNotNull";
         std::abort();
@@ -556,15 +606,31 @@ TEST(notnull_tests, TestMakeNotNull)
 
 TEST(notnull_tests, TestStdHash)
 {
-    int x = 42;
-    int y = 99;
-    not_null<int*> nn{&x};
-    const not_null<int*> cnn{&x};
+    {
+        int x = 42;
+        int y = 99;
+        not_null<int*> nn{&x};
+        const not_null<int*> cnn{&x};
 
-    std::hash<not_null<int*>> hash_nn;
-    std::hash<int*> hash_intptr;
+        std::hash<not_null<int*>> hash_nn;
+        std::hash<int*> hash_intptr;
 
-    EXPECT_TRUE(hash_nn(nn) == hash_intptr(&x));
-    EXPECT_FALSE(hash_nn(nn) == hash_intptr(&y));
-    EXPECT_FALSE(hash_nn(nn) == hash_intptr(nullptr));
+        EXPECT_TRUE(hash_nn(nn) == hash_intptr(&x));
+        EXPECT_FALSE(hash_nn(nn) == hash_intptr(&y));
+        EXPECT_FALSE(hash_nn(nn) == hash_intptr(nullptr));
+    }
+
+    {
+        const int x = 42;
+        const int y = 99;
+        not_null<const int*> nn{&x};
+        const not_null<const int*> cnn{&x};
+
+        std::hash<not_null<const int*>> hash_nn;
+        std::hash<const int*> hash_intptr;
+
+        EXPECT_TRUE(hash_nn(nn) == hash_intptr(&x));
+        EXPECT_FALSE(hash_nn(nn) == hash_intptr(&y));
+        EXPECT_FALSE(hash_nn(nn) == hash_intptr(nullptr));
+    }
 }
diff --git a/tests/strict_notnull_tests.cpp b/tests/strict_notnull_tests.cpp
index 7edef43..c1b1f54 100644
--- a/tests/strict_notnull_tests.cpp
+++ b/tests/strict_notnull_tests.cpp
@@ -71,6 +71,28 @@ TEST(strict_notnull_tests, TestStrictNotNull)
         EXPECT_TRUE(*snn1 == 42);
     }
 
+    {
+        // raw ptr <-> strict_not_null
+        const int x = 42;
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+        strict_not_null<int*> snn = &x;
+        strict_helper(&x);
+        strict_helper_const(&x);
+        strict_helper(return_pointer());
+        strict_helper_const(return_pointer_const());
+#endif
+
+        const strict_not_null<const int*> snn1{&x};
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(snn1);
+#endif
+        helper_const(snn1);
+
+        EXPECT_TRUE(*snn1 == 42);
+    }
+
     {
         // strict_not_null -> strict_not_null
         int x = 42;
@@ -85,6 +107,22 @@ TEST(strict_notnull_tests, TestStrictNotNull)
         EXPECT_TRUE(snn1 == snn2);
     }
 
+    {
+        // strict_not_null -> strict_not_null
+        const int x = 42;
+
+        strict_not_null<const int*> snn1{&x};
+        const strict_not_null<const int*> snn2{&x};
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+        strict_helper(snn1);
+#endif
+        strict_helper_const(snn1);
+        strict_helper_const(snn2);
+
+        EXPECT_TRUE(snn1 == snn2);
+    }
+
     {
         // strict_not_null -> not_null
         int x = 42;
@@ -101,6 +139,24 @@ TEST(strict_notnull_tests, TestStrictNotNull)
         EXPECT_TRUE(snn == nn2);
     }
 
+    {
+        // strict_not_null -> not_null
+        const int x = 42;
+
+        strict_not_null<const int*> snn{&x};
+
+        const not_null<const int*> nn1 = snn;
+        const not_null<const int*> nn2{snn};
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(snn);
+#endif
+        helper_const(snn);
+
+        EXPECT_TRUE(snn == nn1);
+        EXPECT_TRUE(snn == nn2);
+    }
+
     {
         // not_null -> strict_not_null
         int x = 42;
@@ -125,6 +181,32 @@ TEST(strict_notnull_tests, TestStrictNotNull)
         EXPECT_TRUE(hash_snn(snn1) == hash_snn(nn));
     }
 
+    {
+        // not_null -> strict_not_null
+        const int x = 42;
+
+        not_null<const int*> nn{&x};
+
+        const strict_not_null<const int*> snn1{nn};
+        const strict_not_null<const int*> snn2{nn};
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+        strict_helper(nn);
+#endif
+        strict_helper_const(nn);
+
+        EXPECT_TRUE(snn1 == nn);
+        EXPECT_TRUE(snn2 == nn);
+
+        std::hash<strict_not_null<const int*>> hash_snn;
+        std::hash<not_null<const int*>> hash_nn;
+
+        EXPECT_TRUE(hash_nn(snn1) == hash_nn(nn));
+        EXPECT_TRUE(hash_snn(snn1) == hash_nn(nn));
+        EXPECT_TRUE(hash_nn(snn1) == hash_nn(snn2));
+        EXPECT_TRUE(hash_snn(snn1) == hash_snn(nn));
+    }
+
 #ifdef CONFIRM_COMPILATION_ERRORS
     {
         strict_not_null<int*> p{nullptr};
@@ -152,6 +234,18 @@ TEST(strict_notnull_tests, TestStrictNotNullConstructorTypeDeduction)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+
+        strict_not_null x{&i};
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(strict_not_null{&i});
+#endif
+        helper_const(strict_not_null{&i});
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     {
         int i = 42;
         int* p = &i;
@@ -163,6 +257,19 @@ TEST(strict_notnull_tests, TestStrictNotNullConstructorTypeDeduction)
         EXPECT_TRUE(*x == 42);
     }
 
+    {
+        const int i = 42;
+        const int* p = &i;
+
+        strict_not_null x{p};
+#ifdef CONFIRM_COMPILATION_ERRORS
+        helper(strict_not_null{p});
+#endif
+        helper_const(strict_not_null{p});
+
+        EXPECT_TRUE(*x == 42);
+    }
+
     {
         auto workaround_macro = []() {
             int* p1 = nullptr;