diff --git a/src/main/java/org/openjdk/jextract/impl/ConstantBuilder.java b/src/main/java/org/openjdk/jextract/impl/ConstantBuilder.java
index e43281b7..2e8e5ddb 100644
--- a/src/main/java/org/openjdk/jextract/impl/ConstantBuilder.java
+++ b/src/main/java/org/openjdk/jextract/impl/ConstantBuilder.java
@@ -29,7 +29,6 @@
 import java.lang.foreign.GroupLayout;
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.MemoryLayout;
-import java.lang.foreign.MemorySegment;
 import java.lang.foreign.SequenceLayout;
 import java.lang.foreign.StructLayout;
 import java.lang.foreign.ValueLayout;
@@ -81,9 +80,14 @@ private Constant addVarHandle(String javaName, String nativeName, ValueLayout va
                 () -> emitVarHandleField(javaName, nativeName, valueLayout, rootLayoutName, prefixElementNames));
     }
 
-    public Constant addMethodHandle(String javaName, String nativeName, FunctionDescriptor descriptor, boolean isVarargs, boolean virtual) {
+    public Constant addDowncallMethodHandle(String javaName, String nativeName, FunctionDescriptor descriptor, boolean isVarargs, boolean virtual) {
+        return emitIfAbsent(javaName, Constant.Kind.METHOD_HANDLE,
+                () -> emitDowncallMethodHandleField(javaName, nativeName, descriptor, isVarargs, virtual));
+    }
+
+    public Constant addLookupMethodHandle(String javaName, String className, String name, FunctionDescriptor descriptor) {
         return emitIfAbsent(javaName, Constant.Kind.METHOD_HANDLE,
-                () -> emitMethodHandleField(javaName, nativeName, descriptor, isVarargs, virtual));
+                () -> emitUpcallMethodHandleField(javaName, className, name, descriptor));
     }
 
     public Constant addSegment(String javaName, String nativeName, MemoryLayout layout) {
@@ -197,7 +201,7 @@ public Constant emitIfAbsent(String name, Constant.Kind kind, Supplier<Constant>
         return constant;
     }
 
-    private Constant emitMethodHandleField(String javaName, String nativeName, FunctionDescriptor descriptor, boolean isVarargs, boolean virtual) {
+    private Constant emitDowncallMethodHandleField(String javaName, String nativeName, FunctionDescriptor descriptor, boolean isVarargs, boolean virtual) {
         Constant functionDesc = addFunctionDesc(javaName, descriptor);
         incrAlign();
         String fieldName = Constant.Kind.METHOD_HANDLE.fieldName(javaName);
@@ -226,6 +230,21 @@ private Constant emitMethodHandleField(String javaName, String nativeName, Funct
         return new Constant(className(), javaName, Constant.Kind.METHOD_HANDLE);
     }
 
+    private Constant emitUpcallMethodHandleField(String javaName, String className, String methodName, FunctionDescriptor descriptor) {
+        Constant functionDesc = addFunctionDesc(javaName, descriptor);
+        incrAlign();
+        String fieldName = Constant.Kind.METHOD_HANDLE.fieldName(javaName);
+        indent();
+        append(memberMods() + "MethodHandle ");
+        append(fieldName + " = RuntimeHelper.upcallHandle(");
+        append(className + ".class, ");
+        append("\"" + methodName + "\", ");
+        append(functionDesc.accessExpression());
+        append(");\n");
+        decrAlign();
+        return new Constant(className(), javaName, Constant.Kind.METHOD_HANDLE);
+    }
+
     private Constant emitVarHandleField(String javaName, String nativeName, ValueLayout valueLayout,
                                       String rootLayoutName, List<String> prefixElementNames) {
         String layoutAccess = rootLayoutName != null ?
diff --git a/src/main/java/org/openjdk/jextract/impl/FunctionalInterfaceBuilder.java b/src/main/java/org/openjdk/jextract/impl/FunctionalInterfaceBuilder.java
index 98ed83b4..9b900bd0 100644
--- a/src/main/java/org/openjdk/jextract/impl/FunctionalInterfaceBuilder.java
+++ b/src/main/java/org/openjdk/jextract/impl/FunctionalInterfaceBuilder.java
@@ -97,13 +97,14 @@ private void emitFunctionalInterfaceMethod() {
     private void emitFunctionalFactories() {
         emitWithConstantClass(constantBuilder -> {
             Constant functionDesc = constantBuilder.addFunctionDesc(className(), fiDesc);
+            Constant upcallHandle = constantBuilder.addLookupMethodHandle(className() + "_UP", className(), "apply", fiDesc);
             incrAlign();
             indent();
             append(MEMBER_MODS + " MemorySegment allocate(" + className() + " fi, Arena scope) {\n");
             incrAlign();
             indent();
-            append("return RuntimeHelper.upcallStub(" + className() + ".class, fi, " +
-                functionDesc.accessExpression() + ", scope);\n");
+            append("return RuntimeHelper.upcallStub(" +
+                upcallHandle.accessExpression() + ", fi, " + functionDesc.accessExpression() + ", scope);\n");
             decrAlign();
             indent();
             append("}\n");
@@ -113,7 +114,7 @@ private void emitFunctionalFactories() {
 
     private void emitFunctionalFactoryForPointer() {
         emitWithConstantClass(constantBuilder -> {
-            Constant mhConstant = constantBuilder.addMethodHandle(className(), className(),
+            Constant mhConstant = constantBuilder.addDowncallMethodHandle(className() + "_DOWN", className(),
                  fiDesc, false, true);
             incrAlign();
             indent();
diff --git a/src/main/java/org/openjdk/jextract/impl/HeaderFileBuilder.java b/src/main/java/org/openjdk/jextract/impl/HeaderFileBuilder.java
index ab814a45..cbff73e1 100644
--- a/src/main/java/org/openjdk/jextract/impl/HeaderFileBuilder.java
+++ b/src/main/java/org/openjdk/jextract/impl/HeaderFileBuilder.java
@@ -24,7 +24,6 @@
  */
 package org.openjdk.jextract.impl;
 
-import java.lang.foreign.Linker;
 import java.lang.foreign.FunctionDescriptor;
 import java.lang.foreign.GroupLayout;
 import java.lang.foreign.MemorySegment;
@@ -109,7 +108,7 @@ public void addFunction(Declaration.Function funcTree, FunctionDescriptor descri
         boolean isVarargs = funcTree.type().varargs();
 
         emitWithConstantClass(constantBuilder -> {
-            Constant mhConstant = constantBuilder.addMethodHandle(javaName, nativeName, descriptor, isVarargs, false)
+            Constant mhConstant = constantBuilder.addDowncallMethodHandle(javaName, nativeName, descriptor, isVarargs, false)
                     .emitGetter(this, MEMBER_MODS, Constant.QUALIFIED_NAME, nativeName);
             MethodType downcallType = descriptor.toMethodType();
             boolean needsAllocator = descriptor.returnLayout().isPresent() &&
diff --git a/src/main/resources/org/openjdk/jextract/impl/resources/RuntimeHelper.java.template b/src/main/resources/org/openjdk/jextract/impl/resources/RuntimeHelper.java.template
index e91182fb..51a2c5fa 100644
--- a/src/main/resources/org/openjdk/jextract/impl/resources/RuntimeHelper.java.template
+++ b/src/main/resources/org/openjdk/jextract/impl/resources/RuntimeHelper.java.template
@@ -71,11 +71,18 @@ final class RuntimeHelper {
                 orElse(null);
     }
 
-    static <Z> MemorySegment upcallStub(Class<Z> fi, Z z, FunctionDescriptor fdesc, Arena scope) {
+    static MethodHandle upcallHandle(Class<?> fi, String name, FunctionDescriptor fdesc) {
         try {
-            MethodHandle handle = MH_LOOKUP.findVirtual(fi, "apply", fdesc.toMethodType());
-            handle = handle.bindTo(z);
-            return LINKER.upcallStub(handle, fdesc, scope);
+            return MH_LOOKUP.findVirtual(fi, name, fdesc.toMethodType());
+        } catch (Throwable ex) {
+            throw new AssertionError(ex);
+        }
+    }
+
+    static <Z> MemorySegment upcallStub(MethodHandle fiHandle, Z z, FunctionDescriptor fdesc, Arena scope) {
+        try {
+            fiHandle = fiHandle.bindTo(z);
+            return LINKER.upcallStub(fiHandle, fdesc, scope);
         } catch (Throwable ex) {
             throw new AssertionError(ex);
         }