diff --git a/src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DelegateTests.cs b/src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DelegateTests.cs
index 39d3800be714a8..ad42e6970918b1 100644
--- a/src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DelegateTests.cs
+++ b/src/libraries/System.Runtime/tests/System.Runtime.Tests/System/DelegateTests.cs
@@ -1276,6 +1276,24 @@ public static void CreateDelegate10_Nullable_ClosedDelegate()
             AssertExtensions.Throws<ArgumentException>(
                 () => Delegate.CreateDelegate(typeof(NullableIntToString), num, mi));
         }
+
+        [Fact]
+        public static void CreateDelegate_ClosedOverNull_InstanceMethod()
+        {
+            MethodInfo mi = typeof(C).GetMethod(nameof(C.IsThisNull));
+            Func<bool> del = (Func<bool>)Delegate.CreateDelegate(typeof(Func<bool>), null, mi);
+            Assert.Null(del.Target);
+            Assert.True(del());
+        }
+
+        [Fact]
+        public static void CreateDelegate_ClosedOverNull_InstanceMethodViaMethodInfoCreateDelegate()
+        {
+            MethodInfo mi = typeof(C).GetMethod(nameof(C.IsThisNull));
+            Func<bool> del = mi.CreateDelegate<Func<bool>>(null);
+            Assert.Null(del.Target);
+            Assert.True(del());
+        }
         #endregion Tests
 
         #region Test Setup
@@ -1370,6 +1388,11 @@ public static void S(C c)
             {
             }
 
+            public bool IsThisNull()
+            {
+                return this is null;
+            }
+
             private void PrivateInstance()
             {
             }
diff --git a/src/mono/mono/metadata/marshal.c b/src/mono/mono/metadata/marshal.c
index 39d522bb570c6f..9e0e82d02dfebe 100644
--- a/src/mono/mono/metadata/marshal.c
+++ b/src/mono/mono/metadata/marshal.c
@@ -2345,10 +2345,15 @@ mono_marshal_get_delegate_invoke_subtype (MonoMethod *method, MonoDelegate *del)
 		return WRAPPER_SUBTYPE_NONE;
 
 	if (!del->target && mono_method_signature_internal (del->method)->hasthis) {
-		if (!(del->method->flags & METHOD_ATTRIBUTE_VIRTUAL) && !m_class_is_valuetype (del->method->klass) && sig->param_count ==  mono_method_signature_internal (del->method)->param_count + 1)
-			return WRAPPER_SUBTYPE_NONE;
-		else
-			return WRAPPER_SUBTYPE_DELEGATE_INVOKE_VIRTUAL;
+		if (!(del->method->flags & METHOD_ATTRIBUTE_VIRTUAL) && !m_class_is_valuetype (del->method->klass)) {
+			if (sig->param_count == mono_method_signature_internal (del->method)->param_count + 1)
+				/* Open instance delegate: first delegate arg becomes 'this' */
+				return WRAPPER_SUBTYPE_NONE;
+			if (sig->param_count == mono_method_signature_internal (del->method)->param_count)
+				/* Closed over null: target (null) is passed as 'this' via the bound path */
+				return WRAPPER_SUBTYPE_NONE;
+		}
+		return WRAPPER_SUBTYPE_DELEGATE_INVOKE_VIRTUAL;
 	}
 
 	if (mono_method_signature_internal (del->method)->param_count == sig->param_count + 1 && (del->method->flags & METHOD_ATTRIBUTE_STATIC))
@@ -2372,8 +2377,10 @@ mono_marshal_get_delegate_invoke (MonoMethod *method, MonoDelegate *del)
 	sig = mono_signature_no_pinvoke (method);
 
 	if (del && !del->target && del->method && mono_method_signature_internal (del->method)->hasthis) {
-		if (!(del->method->flags & METHOD_ATTRIBUTE_VIRTUAL) && !m_class_is_valuetype (del->method->klass) && sig->param_count ==  mono_method_signature_internal (del->method)->param_count + 1) {
-			/* The first argument of the delegate is passed as this, the normal invoke code can handle this */
+		if (!(del->method->flags & METHOD_ATTRIBUTE_VIRTUAL) && !m_class_is_valuetype (del->method->klass) &&
+		    (sig->param_count == mono_method_signature_internal (del->method)->param_count + 1 ||
+		     sig->param_count == mono_method_signature_internal (del->method)->param_count)) {
+			/* Open instance delegate or closed over null: the normal invoke code can handle this */
 		} else {
 			callvirt = TRUE;
 		}
diff --git a/src/mono/mono/mini/interp/interp.c b/src/mono/mono/mini/interp/interp.c
index 0a12875dcce179..bb8020515fa5bb 100644
--- a/src/mono/mono/mini/interp/interp.c
+++ b/src/mono/mono/mini/interp/interp.c
@@ -4355,6 +4355,9 @@ mono_interp_exec_method (InterpFrame *frame, ThreadContext *context, FrameClause
 					} else {
 						LOCAL_VAR (call_args_offset, MonoObject*) = this_arg;
 					}
+				} else if (!m_method_is_static (cmethod->method) && cmethod->param_count == param_count) {
+					// Closed over null: instance method bound with null this
+					LOCAL_VAR (call_args_offset, MonoObject*) = NULL;
 				} else {
 					// skip the delegate pointer for static calls
 					// FIXME we could avoid memmove
diff --git a/src/mono/mono/mini/llvmonly-runtime.c b/src/mono/mono/mini/llvmonly-runtime.c
index 92b8c65ece72d3..1d1023fbd35d74 100644
--- a/src/mono/mono/mini/llvmonly-runtime.c
+++ b/src/mono/mono/mini/llvmonly-runtime.c
@@ -817,6 +817,12 @@ mini_llvmonly_init_delegate (MonoDelegate *del, MonoDelegateTrampInfo *info)
 	if (subtype == WRAPPER_SUBTYPE_DELEGATE_INVOKE_BOUND)
 		del->bound = TRUE;
 
+	/* Closed over null: instance method bound with null target.
+	 * Set bound so the wrapper passes target (null) as 'this'. */
+	if (!del->target && del->method && mono_method_signature_internal (del->method)->hasthis &&
+	    mono_method_signature_internal (info->invoke)->param_count == mono_method_signature_internal (del->method)->param_count)
+		del->bound = TRUE;
+
 	ftndesc = info->invoke_impl;
 	if (G_UNLIKELY (!ftndesc) || subtype != WRAPPER_SUBTYPE_NONE) {
 		MonoMethod *invoke_impl = mono_marshal_get_delegate_invoke (info->invoke, del);
diff --git a/src/mono/mono/mini/mini-trampolines.c b/src/mono/mono/mini/mini-trampolines.c
index 2abe69f98eef25..7ece3ffa9deac6 100644
--- a/src/mono/mono/mini/mini-trampolines.c
+++ b/src/mono/mono/mini/mini-trampolines.c
@@ -1076,6 +1076,15 @@ mono_delegate_trampoline (host_mgreg_t *regs, guint8 *code, gpointer *arg, guint
 		if (m_method_is_static (method) && sig->param_count == tramp_info->invoke_sig->param_count + 1)
 			closed_static = TRUE;
 
+		if (callvirt && closed_over_null) {
+			if (!m_method_is_virtual (method) && !m_class_is_valuetype (method->klass)) {
+				/* Closed over null with non-virtual instance method: use the bound path */
+				callvirt = FALSE;
+				delegate->bound = TRUE;
+				enable_caching = FALSE;
+			}
+		}
+
 		if (callvirt && !closed_over_null) {
 			/*
 			 * The delegate needs to make a virtual call to the target method using its
@@ -1136,7 +1145,7 @@ mono_delegate_trampoline (host_mgreg_t *regs, guint8 *code, gpointer *arg, guint
 
 	multicast = ((MonoMulticastDelegate*)delegate)->delegates != NULL;
 	if (!multicast && !callvirt) {
-		if (closed_static)
+		if (closed_static || closed_over_null)
 			invoke_impl = impl_this;
 		else
 			invoke_impl = delegate->target ? impl_this : impl_nothis;