diff --git a/org.lflang/src/org/lflang/generator/c/CGenerator.java b/org.lflang/src/org/lflang/generator/c/CGenerator.java
index 8d537798a0..4ba439fc01 100644
--- a/org.lflang/src/org/lflang/generator/c/CGenerator.java
+++ b/org.lflang/src/org/lflang/generator/c/CGenerator.java
@@ -2231,6 +2231,8 @@ private void generateModeStructure(ReactorInstance instance) {
      */
     public void generateParameterInitialization(ReactorInstance instance) {
         var selfRef = CUtil.reactorRef(instance);
+        // Declare a local bank_index variable so that initializers can use it.
+        initializeTriggerObjects.pr("int bank_index = "+CUtil.bankIndex(instance)+";");
         for (ParameterInstance parameter : instance.parameters) {
             // NOTE: we now use the resolved literal value. For better efficiency, we could
             // store constants in a global array and refer to its elements to avoid duplicate
diff --git a/org.lflang/src/org/lflang/generator/python/PythonReactorGenerator.java b/org.lflang/src/org/lflang/generator/python/PythonReactorGenerator.java
index be06af5254..98d95f98f0 100644
--- a/org.lflang/src/org/lflang/generator/python/PythonReactorGenerator.java
+++ b/org.lflang/src/org/lflang/generator/python/PythonReactorGenerator.java
@@ -147,6 +147,9 @@ public static String generatePythonClassInstantiations(ReactorInstance instance,
                 "for "+PyUtil.bankIndexName(instance)+" in range("+instance.getWidth()+"):"
             ));
             code.indent();
+            // Define a bank_index local variable so that it can be used while
+            // setting parameter values.
+            code.pr("bank_index = "+PyUtil.bankIndexName(instance));
             code.pr(generatePythonClassInstantiation(instance, className));
         }
 
diff --git a/test/C/src/multiport/BankIndexInitializer.lf b/test/C/src/multiport/BankIndexInitializer.lf
new file mode 100644
index 0000000000..2a66a41432
--- /dev/null
+++ b/test/C/src/multiport/BankIndexInitializer.lf
@@ -0,0 +1,43 @@
+// Test bank of reactors to multiport input with id parameter in the bank.
+target C;
+
+preamble {=
+    int table[] = {4, 3, 2, 1};
+=}
+
+reactor Source(
+    bank_index:int(0),
+    value:int(0)
+) {
+    output out:int;
+    reaction (startup) -> out {=
+        SET(out, self->value);
+    =}
+}
+
+reactor Sink(width:int(4)) {
+    input[width] in:int;
+    state received:bool(false);
+    
+    reaction (in) {=
+        for (int idx = 0; idx < in_width; idx++) {
+            if (in[idx]->is_present) {
+                printf("Received on channel %d: %d\n", idx, in[idx]->value);
+                self->received = true;
+                if (in[idx]->value != 4 - idx) {
+                    error_print_and_exit("Expected %d.", 4 - idx);
+                }
+            }
+        }
+    =}
+    reaction(shutdown) {=
+        if (!self->received) {
+            error_print_and_exit("Sink received no data.");
+        }
+    =}
+}
+main reactor(width:int(4)) {
+    source = new[width] Source(value = {= table[bank_index] =});
+    sink = new Sink(width = width);
+    source.out -> sink.in;
+}
\ No newline at end of file
diff --git a/test/Python/src/multiport/BankIndexInitializer.lf b/test/Python/src/multiport/BankIndexInitializer.lf
new file mode 100644
index 0000000000..54fb4c16ce
--- /dev/null
+++ b/test/Python/src/multiport/BankIndexInitializer.lf
@@ -0,0 +1,41 @@
+// Test bank of reactors to multiport input with id parameter in the bank.
+target Python;
+
+preamble {=
+    table = [4, 3, 2, 1]
+=}
+
+reactor Source(
+    bank_index(0),
+    value(0)
+) {
+    output out;
+    reaction (startup) -> out {=
+        out.set(self.value)
+    =}
+}
+
+reactor Sink(width(4)) {
+    input[width] _in;
+    state received(false);
+    
+    reaction (_in) {=
+        for (idx, port) in enumerate(_in):
+            if port.is_present is True:
+                print("Received on channel {:d}: {:d}".format(idx, port.value))
+                self.received = True
+                if port.value != 4 - idx:
+                    sys.stderr.write("ERROR: expected {:d}\n".format(4 - idx))
+                    exit(1)
+    =}
+    reaction(shutdown) {=
+        if self.received is False:
+            sys.stderr.write("ERROR: Sink received no data\n")
+            exit(1)
+    =}
+}
+main reactor(width(4)) {
+    source = new[width] Source(value = {= table[bank_index] =});
+    sink = new Sink(width = width);
+    source.out -> sink._in;
+}
\ No newline at end of file