diff --git a/src/coreclr/jit/importercalls.cpp b/src/coreclr/jit/importercalls.cpp
index 603cd256109134..23ceed3cde357d 100644
--- a/src/coreclr/jit/importercalls.cpp
+++ b/src/coreclr/jit/importercalls.cpp
@@ -10638,17 +10638,16 @@ NamedIntrinsic Compiler::lookupNamedIntrinsic(CORINFO_METHOD_HANDLE method)
 
                         if (isVectorT || (strcmp(className, "Vector") == 0))
                         {
-                            if (strncmp(methodName,
-                                        "System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector",
-                                        70) == 0)
+                            if (strncmp(methodName, "System.Runtime.Intrinsics.ISimdVector<System.Numerics.Vector",
+                                        60) == 0)
                             {
                                 // We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where
                                 // possible but, they all prefix the qualified name of the interface first, so we'll
                                 // check for that and skip the prefix before trying to resolve the method.
 
-                                if (strncmp(methodName + 70, "<T>,T>.", 7) == 0)
+                                if (strncmp(methodName + 60, "<T>,T>.", 7) == 0)
                                 {
-                                    methodName += 77;
+                                    methodName += 67;
                                 }
                             }
 
diff --git a/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs b/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs
index 70dde2b702ea3b..a0a98dc9fae023 100644
--- a/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs
+++ b/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs
@@ -4421,29 +4421,38 @@ private bool notifyInstructionSetUsage(InstructionSet instructionSet, bool suppo
                 }
                 else
                 {
+                    // We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
+                    // but, they all prefix the qualified name of the interface first, so we'll check for that and
+                    // skip the prefix before trying to resolve the method.
                     ReadOnlySpan<char> methodName = MethodBeingCompiled.Name.AsSpan();
 
-                    if (methodName.StartsWith("System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector"))
+                    if (methodName.StartsWith("System.Runtime.Intrinsics.ISimdVector<System."))
                     {
-                        // We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
-                        // but, they all prefix the qualified name of the interface first, so we'll check for that and
-                        // skip the prefix before trying to resolve the method.
+                        ReadOnlySpan<char> partialMethodName = methodName.Slice(45);
 
-                        ReadOnlySpan<char> partialMethodName = methodName.Slice(70);
-
-                        if (partialMethodName.StartsWith("<T>,T>."))
-                        {
-                            methodName = partialMethodName.Slice(7);
-                        }
-                        else if (partialMethodName.StartsWith("64<T>,T>."))
+                        if (partialMethodName.StartsWith("Numerics.Vector"))
                         {
-                            methodName = partialMethodName.Slice(9);
+                            partialMethodName = partialMethodName.Slice(15);
+
+                            if (partialMethodName.StartsWith("<T>,T>."))
+                            {
+                                methodName = partialMethodName.Slice(7);
+                            }
                         }
-                        else if (partialMethodName.StartsWith("128<T>,T>.") ||
-                                 partialMethodName.StartsWith("256<T>,T>.") ||
-                                 partialMethodName.StartsWith("512<T>,T>."))
+                        if (partialMethodName.StartsWith("Runtime.Intrinsics.Vector"))
                         {
-                            methodName = partialMethodName.Slice(10);
+                            partialMethodName = partialMethodName.Slice(25);
+
+                            if (partialMethodName.StartsWith("64<T>,T>."))
+                            {
+                                methodName = partialMethodName.Slice(9);
+                            }
+                            else if (partialMethodName.StartsWith("128<T>,T>.") ||
+                                    partialMethodName.StartsWith("256<T>,T>.") ||
+                                    partialMethodName.StartsWith("512<T>,T>."))
+                            {
+                                methodName = partialMethodName.Slice(10);
+                            }
                         }
                     }
 
diff --git a/src/mono/mono/mini/interp/transform-simd.c b/src/mono/mono/mini/interp/transform-simd.c
index f98cc584b8dea5..f7496ce839f9ea 100644
--- a/src/mono/mono/mini/interp/transform-simd.c
+++ b/src/mono/mono/mini/interp/transform-simd.c
@@ -679,20 +679,25 @@ static gboolean
 emit_sn_vector_t (TransformData *td, MonoMethod *cmethod, MonoMethodSignature *csignature, gboolean newobj)
 {
 	const char *cmethod_name = cmethod->name;
+	bool explicitly_implemented = false;
 
-	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector", 70) == 0) {
+	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.Numerics.Vector<T>,T>.", 67) == 0) {
 		// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
 		// but, they all prefix the qualified name of the interface first, so we'll check for that and
 		// skip the prefix before trying to resolve the method.
 
-		if (strncmp(cmethod_name + 70, "<T>,T>.", 7) == 0) {
-			cmethod_name += 77;
-		}
+		cmethod_name += 67;
+		explicitly_implemented = true;
 	}
 
 	int id = lookup_intrins (sn_vector_t_methods, sizeof (sn_vector_t_methods), cmethod_name);
-	if (id == -1)
-		return FALSE;
+	if (id == -1) {
+		if (explicitly_implemented) {
+			return emit_sri_vector128 (td, cmethod, csignature);
+		} else {
+			return FALSE;
+		}
+	}
 
 	gint16 simd_opcode = -1;
 	gint16 simd_intrins = -1;
diff --git a/src/mono/mono/mini/intrinsics.c b/src/mono/mono/mini/intrinsics.c
index 046dfa79e5b0a7..6b8e8642259826 100644
--- a/src/mono/mono/mini/intrinsics.c
+++ b/src/mono/mono/mini/intrinsics.c
@@ -2396,19 +2396,21 @@ mini_emit_inst_for_method (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSign
 		!strncmp ("System.Runtime.Intrinsics", cmethod_klass_name_space, 25))) {
 		const char* cmethod_name = cmethod->name;
 
-		if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector", 70) == 0) {
-			// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
-			// but, they all prefix the qualified name of the interface first, so we'll check for that and
-			// skip the prefix before trying to resolve the method.
-
-			if (strncmp(cmethod_name + 70, "<T>,T>.", 7) == 0) {
-				cmethod_name += 77;
-			} else if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
-				cmethod_name += 79;
-			} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
-				(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
-				(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
-				cmethod_name += 80;
+		if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.", 45) == 0) {
+			if (strncmp(cmethod_name + 45, "Runtime.Intrinsics.Vector", 25) == 0) {
+				// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
+				// but, they all prefix the qualified name of the interface first, so we'll check for that and
+				// skip the prefix before trying to resolve the method.
+
+				if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
+					cmethod_name += 79;
+				} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
+					(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
+					(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
+					cmethod_name += 80;
+				}
+			} else if (strncmp(cmethod_name + 45, "Numerics.Vector<T>,T>.", 22) == 0) {
+				cmethod_name += 67;
 			}
 		}
 
diff --git a/src/mono/mono/mini/simd-intrinsics.c b/src/mono/mono/mini/simd-intrinsics.c
index d5303b4f9542be..f9d8d4b59ef559 100644
--- a/src/mono/mono/mini/simd-intrinsics.c
+++ b/src/mono/mono/mini/simd-intrinsics.c
@@ -1906,19 +1906,21 @@ emit_sri_vector (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *fsi
 {
 	const char *cmethod_name = cmethod->name;
 
-	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector", 70) == 0) {
+	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.", 45) == 0) {
+		if (strncmp (cmethod_name + 45, "Runtime.Intrinsics.Vector", 25) == 0) {
 		// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
 		// but, they all prefix the qualified name of the interface first, so we'll check for that and
 		// skip the prefix before trying to resolve the method.
 
-		if (strncmp(cmethod_name + 70, "<T>,T>.", 7) == 0) {
-			cmethod_name += 77;
-		} else if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
-			cmethod_name += 79;
-		} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
-			(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
-			(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
-			cmethod_name += 80;
+			if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
+				cmethod_name += 79;
+			} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
+				(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
+				(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
+				cmethod_name += 80;
+			}
+		} else if (strncmp(cmethod_name + 45, "Numerics.Vector<T>,T>.", 22) == 0) {
+			cmethod_name += 67;
 		}
 	}
 
@@ -2437,7 +2439,7 @@ emit_sri_vector (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *fsi
 
 			const char *klass_name = m_class_get_name (klass);
 
-			if (!strcmp (klass_name, "Vector4")) {
+			if (strcmp (m_class_get_name_space (klass), "System.Runtime.Intrinsics") != 0) {
 				klass_name = "Vector128`1";
 			}
 			arg_class = create_class_instance ("System.Runtime.Intrinsics", klass_name, m_class_get_byval_arg (cast_class));
@@ -3371,21 +3373,23 @@ emit_sri_vector_t (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *f
 	const char *cmethod_name = cmethod->name;
 	bool explicitly_implemented = false;
 
-	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.Runtime.Intrinsics.Vector", 70) == 0) {
-		// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
-		// but, they all prefix the qualified name of the interface first, so we'll check for that and
-		// skip the prefix before trying to resolve the method.
-
-		if (strncmp(cmethod_name + 70, "<T>,T>.", 7) == 0) {
-			cmethod_name += 77;
-			explicitly_implemented = true;
-		} else if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
-			cmethod_name += 79;
-			explicitly_implemented = true;
-		} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
-			(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
-			(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
-			cmethod_name += 80;
+	if (strncmp(cmethod_name, "System.Runtime.Intrinsics.ISimdVector<System.", 45) == 0) {
+		if (strncmp(cmethod_name + 45, "Runtime.Intrinsics.Vector", 25) == 0) {
+			// We want explicitly implemented ISimdVector<TSelf, T> APIs to still be expanded where possible
+			// but, they all prefix the qualified name of the interface first, so we'll check for that and
+			// skip the prefix before trying to resolve the method.
+
+			if (strncmp(cmethod_name + 70, "64<T>,T>.", 9) == 0) {
+				cmethod_name += 79;
+				explicitly_implemented = true;
+			} else if ((strncmp(cmethod_name + 70, "128<T>,T>.", 10) == 0) ||
+				(strncmp(cmethod_name + 70, "256<T>,T>.", 10) == 0) ||
+				(strncmp(cmethod_name + 70, "512<T>,T>.", 10) == 0)) {
+				cmethod_name += 80;
+				explicitly_implemented = true;
+			}
+		} else if (strncmp(cmethod_name + 45, "Numerics.Vector<T>,T>.", 22) == 0) {
+			cmethod_name += 67;
 			explicitly_implemented = true;
 		}
 	}