diff --git a/src/factories/offline-audio-buffer-source-node.ts b/src/factories/offline-audio-buffer-source-node.ts
index a5807daa7..fc6efade6 100644
--- a/src/factories/offline-audio-buffer-source-node.ts
+++ b/src/factories/offline-audio-buffer-source-node.ts
@@ -218,9 +218,12 @@ export class OfflineAudioBufferSourceNodeFaker implements IOfflineAudioNodeFaker
 
         const promises = Array
             .from(this._sources)
-            .map(([ source, { input, output } ]) => source
-                .render(offlineAudioContext)
-                .then((node) => node.connect(<AudioBufferSourceNode> this._node, output, input)));
+            .map(([ source, { input, output } ]) => {
+                // For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an error.
+                return source
+                    .render(offlineAudioContext)
+                    .then((node) => node.connect(<AudioBufferSourceNode> this._node, output, input));
+            });
 
         return Promise
             .all(promises)
diff --git a/src/factories/offline-audio-destination-node.ts b/src/factories/offline-audio-destination-node.ts
index 489017b37..bfef42e46 100644
--- a/src/factories/offline-audio-destination-node.ts
+++ b/src/factories/offline-audio-destination-node.ts
@@ -68,9 +68,12 @@ export class OfflineAudioDestinationNodeFaker implements IOfflineAudioNodeFaker
 
         const promises = Array
             .from(this._sources)
-            .map(([ source, { input, output } ]) => source
-                .render(offlineAudioContext)
-                .then((node) => node.connect(<AudioDestinationNode> this._node, output, input)));
+            .map(([ source, { input, output } ]) => {
+                // For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an error.
+                return source
+                    .render(offlineAudioContext)
+                    .then((node) => node.connect(<AudioDestinationNode> this._node, output, input));
+            });
 
         return Promise
             .all(promises)
diff --git a/src/factories/offline-biquad-filter-node.ts b/src/factories/offline-biquad-filter-node.ts
index 2fa2191db..64de74e71 100644
--- a/src/factories/offline-biquad-filter-node.ts
+++ b/src/factories/offline-biquad-filter-node.ts
@@ -275,9 +275,12 @@ export class OfflineBiquadFilterNodeFaker implements IOfflineAudioNodeFaker {
 
         const promises = Array
             .from(this._sources)
-            .map(([ source, { input, output } ]) => source
-                .render(offlineAudioContext)
-                .then((node) => node.connect(<BiquadFilterNode> this._node, output, input)));
+            .map(([ source, { input, output } ]) => {
+                // For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an error.
+                return source
+                    .render(offlineAudioContext)
+                    .then((node) => node.connect(<BiquadFilterNode> this._node, output, input));
+            });
 
         return Promise
             .all(promises)
diff --git a/src/factories/offline-gain-node.ts b/src/factories/offline-gain-node.ts
index b3f64389e..048e7f7fd 100644
--- a/src/factories/offline-gain-node.ts
+++ b/src/factories/offline-gain-node.ts
@@ -109,9 +109,12 @@ export class OfflineGainNodeFaker implements IOfflineAudioNodeFaker {
 
         const promises = Array
             .from(this._sources)
-            .map(([ source, { input, output } ]) => source
-                .render(offlineAudioContext)
-                .then((node) => node.connect(<GainNode> this._node, output, input)));
+            .map(([ source, { input, output } ]) => {
+                // For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an error.
+                return source
+                    .render(offlineAudioContext)
+                    .then((node) => node.connect(<GainNode> this._node, output, input));
+            });
 
         return Promise
             .all(promises)
diff --git a/src/factories/offline-iir-filter-node.ts b/src/factories/offline-iir-filter-node.ts
index d3c4fff65..9c99617c3 100644
--- a/src/factories/offline-iir-filter-node.ts
+++ b/src/factories/offline-iir-filter-node.ts
@@ -327,9 +327,15 @@ export class OfflineIIRFilterNodeFaker implements IOfflineAudioNodeFaker {
 
             const promises = Array
                 .from(this._sources)
-                .map(([ source, { input, output } ]) => source
-                    .render(offlineAudioContext)
-                    .then((node) => node.connect(<IIRFilterNode> this._node, output, input)));
+                .map(([ source, { input, output } ]) => {
+                    /*
+                     * For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an
+                     * error.
+                     */
+                    return source
+                        .render(offlineAudioContext)
+                        .then((node) => node.connect(<IIRFilterNode> this._node, output, input));
+                });
 
             return Promise
                 .all(promises)
@@ -345,9 +351,12 @@ export class OfflineIIRFilterNodeFaker implements IOfflineAudioNodeFaker {
 
         const promises = Array
             .from(this._sources)
-            .map(([ source, { input, output } ]) => source
-                .render(partialOfflineAudioContext)
-                .then((node) => node.connect(partialOfflineAudioContext.destination, output, input)));
+            .map(([ source, { input, output } ]) => {
+                // For some reason this currently needs to be a function body with a return statement. The shortcut syntax causes an error.
+                return source
+                    .render(partialOfflineAudioContext)
+                    .then((node) => node.connect(partialOfflineAudioContext.destination, output, input));
+            });
 
         return Promise
             .all(promises)