diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioBufferSourceNode.h b/Userland/Libraries/LibWeb/WebAudio/AudioBufferSourceNode.h
index 52dac427362..c6cb9bbe412 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioBufferSourceNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioBufferSourceNode.h
@@ -41,6 +41,8 @@ public:
     double loop_start() const;
     WebIDL::ExceptionOr<void> set_loop_end(double);
     double loop_end() const;
+    WebIDL::UnsignedLong number_of_inputs() override { return 0; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 2; }
 
     WebIDL::ExceptionOr<void> start(Optional<double>, Optional<double>, Optional<double>);
 
diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioDestinationNode.h b/Userland/Libraries/LibWeb/WebAudio/AudioDestinationNode.h
index 0f20bc54fc1..d2fcfe0709a 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioDestinationNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioDestinationNode.h
@@ -23,6 +23,8 @@ public:
     virtual ~AudioDestinationNode() override;
 
     WebIDL::UnsignedLong max_channel_count();
+    WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
 
     static JS::NonnullGCPtr<AudioDestinationNode> construct_impl(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>);
 
diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioNode.cpp b/Userland/Libraries/LibWeb/WebAudio/AudioNode.cpp
index 67af990712a..fcb3284cce2 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioNode.cpp
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioNode.cpp
@@ -98,20 +98,6 @@ void AudioNode::disconnect(JS::NonnullGCPtr<AudioParam> destination_param, WebID
     dbgln("FIXME: Implement AudioNode::disconnect(destination_param, output)");
 }
 
-// https://webaudio.github.io/web-audio-api/#dom-audionode-numberofinputs
-WebIDL::UnsignedLong AudioNode::number_of_inputs()
-{
-    dbgln("FIXME: Implement AudioNode::number_of_inputs()");
-    return 0;
-}
-
-// https://webaudio.github.io/web-audio-api/#dom-audionode-numberofoutputs
-WebIDL::UnsignedLong AudioNode::number_of_outputs()
-{
-    dbgln("FIXME: Implement AudioNode::number_of_outputs()");
-    return 0;
-}
-
 // https://webaudio.github.io/web-audio-api/#dom-audionode-channelcount
 WebIDL::ExceptionOr<void> AudioNode::set_channel_count(WebIDL::UnsignedLong channel_count)
 {
diff --git a/Userland/Libraries/LibWeb/WebAudio/AudioNode.h b/Userland/Libraries/LibWeb/WebAudio/AudioNode.h
index 0c9e39830d9..1f09f0ab7d5 100644
--- a/Userland/Libraries/LibWeb/WebAudio/AudioNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/AudioNode.h
@@ -48,8 +48,11 @@ public:
         return m_context;
     }
 
-    WebIDL::UnsignedLong number_of_inputs();
-    WebIDL::UnsignedLong number_of_outputs();
+    // https://webaudio.github.io/web-audio-api/#dom-audionode-numberofinputs
+    virtual WebIDL::UnsignedLong number_of_inputs() = 0;
+    // https://webaudio.github.io/web-audio-api/#dom-audionode-numberofoutputs
+    virtual WebIDL::UnsignedLong number_of_outputs() = 0;
+
     WebIDL::ExceptionOr<void> set_channel_count(WebIDL::UnsignedLong);
     WebIDL::UnsignedLong channel_count();
     WebIDL::ExceptionOr<void> set_channel_count_mode(Bindings::ChannelCountMode);
diff --git a/Userland/Libraries/LibWeb/WebAudio/BiquadFilterNode.h b/Userland/Libraries/LibWeb/WebAudio/BiquadFilterNode.h
index a401c4cbef5..952b39f03d2 100644
--- a/Userland/Libraries/LibWeb/WebAudio/BiquadFilterNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/BiquadFilterNode.h
@@ -29,6 +29,9 @@ class BiquadFilterNode : public AudioNode {
 public:
     virtual ~BiquadFilterNode() override;
 
+    WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
     WebIDL::ExceptionOr<void> set_type(Bindings::BiquadFilterType);
     Bindings::BiquadFilterType type() const;
     JS::NonnullGCPtr<AudioParam> frequency() const;
diff --git a/Userland/Libraries/LibWeb/WebAudio/DynamicsCompressorNode.h b/Userland/Libraries/LibWeb/WebAudio/DynamicsCompressorNode.h
index 78af0b59294..1a4a0661556 100644
--- a/Userland/Libraries/LibWeb/WebAudio/DynamicsCompressorNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/DynamicsCompressorNode.h
@@ -30,6 +30,9 @@ public:
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<DynamicsCompressorNode>> create(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>, DynamicsCompressorOptions const& = {});
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<DynamicsCompressorNode>> construct_impl(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>, DynamicsCompressorOptions const& = {});
 
+    WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
     JS::NonnullGCPtr<AudioParam const> threshold() const { return m_threshold; }
     JS::NonnullGCPtr<AudioParam const> knee() const { return m_knee; }
     JS::NonnullGCPtr<AudioParam const> ratio() const { return m_ratio; }
diff --git a/Userland/Libraries/LibWeb/WebAudio/GainNode.h b/Userland/Libraries/LibWeb/WebAudio/GainNode.h
index 13fd5c64265..2e28cbc059d 100644
--- a/Userland/Libraries/LibWeb/WebAudio/GainNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/GainNode.h
@@ -27,6 +27,9 @@ public:
     static JS::NonnullGCPtr<GainNode> create(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>, GainOptions const& = {});
     static JS::NonnullGCPtr<GainNode> construct_impl(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>, GainOptions const& = {});
 
+    WebIDL::UnsignedLong number_of_inputs() override { return 1; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
+
     JS::NonnullGCPtr<AudioParam const> gain() const { return m_gain; }
 
 protected:
diff --git a/Userland/Libraries/LibWeb/WebAudio/OscillatorNode.h b/Userland/Libraries/LibWeb/WebAudio/OscillatorNode.h
index 4311b0f007b..6bd32cac0f4 100644
--- a/Userland/Libraries/LibWeb/WebAudio/OscillatorNode.h
+++ b/Userland/Libraries/LibWeb/WebAudio/OscillatorNode.h
@@ -34,6 +34,8 @@ public:
     WebIDL::ExceptionOr<void> set_type(Bindings::OscillatorType);
 
     JS::NonnullGCPtr<AudioParam const> frequency() const { return m_frequency; }
+    WebIDL::UnsignedLong number_of_inputs() override { return 0; }
+    WebIDL::UnsignedLong number_of_outputs() override { return 1; }
 
 protected:
     OscillatorNode(JS::Realm&, JS::NonnullGCPtr<BaseAudioContext>, OscillatorOptions const& = {});