diff --git a/src/core/lib/ImageManipulation.mjs b/src/core/lib/ImageManipulation.mjs
index 1f1b85ae..54c1bafc 100644
--- a/src/core/lib/ImageManipulation.mjs
+++ b/src/core/lib/ImageManipulation.mjs
@@ -12,7 +12,7 @@ import OperationError from "../errors/OperationError";
  * Gaussian blurs an image.
  *
  * @param {jimp} input
- * @param {int} radius
+ * @param {number} radius
  * @param {boolean} fast
  * @returns {jimp}
  */
@@ -24,7 +24,6 @@ export function gaussianBlur (input, radius) {
             input = boxBlur(input, (boxes[i] - 1) / 2);
         }
     } catch (err) {
-        log.error(err);
         throw new OperationError(`Error blurring image. (${err})`);
     }
 
@@ -33,8 +32,8 @@ export function gaussianBlur (input, radius) {
 
 /**
  *
- * @param {int} radius
- * @param {int} numBoxes
+ * @param {number} radius
+ * @param {number} numBoxes
  * @returns {Array}
  */
 function boxesForGauss(radius, numBoxes) {
@@ -167,9 +166,9 @@ function boxBlurH (source, output, width, height, radius) {
  *
  * @param {jimp} source
  * @param {jimp} output
- * @param {int} width
- * @param {int} height
- * @param {int} radius
+ * @param {number} width
+ * @param {number} height
+ * @param {number} radius
  * @returns {jimp}
  */
 function boxBlurV (source, output, width, height, radius) {
diff --git a/src/core/operations/AddTextToImage.mjs b/src/core/operations/AddTextToImage.mjs
index f8ee3485..68a28c8f 100644
--- a/src/core/operations/AddTextToImage.mjs
+++ b/src/core/operations/AddTextToImage.mjs
@@ -228,7 +228,12 @@ class AddTextToImage extends Operation {
                 }
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error adding text to image. (${err})`);
diff --git a/src/core/operations/BlurImage.mjs b/src/core/operations/BlurImage.mjs
index e0b5c919..68c8dbd6 100644
--- a/src/core/operations/BlurImage.mjs
+++ b/src/core/operations/BlurImage.mjs
@@ -76,7 +76,12 @@ class BlurImage extends Operation {
                     break;
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error blurring image. (${err})`);
diff --git a/src/core/operations/ContainImage.mjs b/src/core/operations/ContainImage.mjs
index 4cb7cfdf..e16d3d58 100644
--- a/src/core/operations/ContainImage.mjs
+++ b/src/core/operations/ContainImage.mjs
@@ -127,7 +127,12 @@ class ContainImage extends Operation {
                 image = newImage;
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error containing image. (${err})`);
diff --git a/src/core/operations/CoverImage.mjs b/src/core/operations/CoverImage.mjs
index 07466308..492938ff 100644
--- a/src/core/operations/CoverImage.mjs
+++ b/src/core/operations/CoverImage.mjs
@@ -115,7 +115,12 @@ class CoverImage extends Operation {
             if (ENVIRONMENT_IS_WORKER())
                 self.sendStatusMessage("Covering image...");
             image.cover(width, height, alignMap[hAlign] | alignMap[vAlign], resizeMap[alg]);
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error covering image. (${err})`);
diff --git a/src/core/operations/CropImage.mjs b/src/core/operations/CropImage.mjs
index efbf29f9..fd04a907 100644
--- a/src/core/operations/CropImage.mjs
+++ b/src/core/operations/CropImage.mjs
@@ -116,7 +116,12 @@ class CropImage extends Operation {
                 image.crop(xPos, yPos, width, height);
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error cropping image. (${err})`);
diff --git a/src/core/operations/DitherImage.mjs b/src/core/operations/DitherImage.mjs
index 13011837..3e603016 100644
--- a/src/core/operations/DitherImage.mjs
+++ b/src/core/operations/DitherImage.mjs
@@ -51,7 +51,13 @@ class DitherImage extends Operation {
             if (ENVIRONMENT_IS_WORKER())
                 self.sendStatusMessage("Applying dither to image...");
             image.dither565();
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error applying dither to image. (${err})`);
diff --git a/src/core/operations/FlipImage.mjs b/src/core/operations/FlipImage.mjs
index 593809e9..cebba0e0 100644
--- a/src/core/operations/FlipImage.mjs
+++ b/src/core/operations/FlipImage.mjs
@@ -66,7 +66,12 @@ class FlipImage extends Operation {
                     break;
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error flipping image. (${err})`);
diff --git a/src/core/operations/ImageBrightnessContrast.mjs b/src/core/operations/ImageBrightnessContrast.mjs
index 27a30cff..f47134a2 100644
--- a/src/core/operations/ImageBrightnessContrast.mjs
+++ b/src/core/operations/ImageBrightnessContrast.mjs
@@ -75,7 +75,12 @@ class ImageBrightnessContrast extends Operation {
                 image.contrast(contrast / 100);
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error adjusting image brightness or contrast. (${err})`);
diff --git a/src/core/operations/ImageFilter.mjs b/src/core/operations/ImageFilter.mjs
index aca34042..6c1a5a65 100644
--- a/src/core/operations/ImageFilter.mjs
+++ b/src/core/operations/ImageFilter.mjs
@@ -66,7 +66,12 @@ class ImageFilter extends Operation {
                 image.sepia();
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error applying filter to image. (${err})`);
diff --git a/src/core/operations/ImageHueSaturationLightness.mjs b/src/core/operations/ImageHueSaturationLightness.mjs
index bca73c30..4bdd9fa7 100644
--- a/src/core/operations/ImageHueSaturationLightness.mjs
+++ b/src/core/operations/ImageHueSaturationLightness.mjs
@@ -102,7 +102,13 @@ class ImageHueSaturationLightness extends Operation {
                     }
                 ]);
             }
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error adjusting image hue / saturation / lightness. (${err})`);
diff --git a/src/core/operations/ImageOpacity.mjs b/src/core/operations/ImageOpacity.mjs
index 999ad176..afa370ff 100644
--- a/src/core/operations/ImageOpacity.mjs
+++ b/src/core/operations/ImageOpacity.mjs
@@ -61,7 +61,12 @@ class ImageOpacity extends Operation {
                 self.sendStatusMessage("Changing image opacity...");
             image.opacity(opacity / 100);
 
-            const imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error changing image opacity. (${err})`);
diff --git a/src/core/operations/InvertImage.mjs b/src/core/operations/InvertImage.mjs
index ed97523f..7c7a4d09 100644
--- a/src/core/operations/InvertImage.mjs
+++ b/src/core/operations/InvertImage.mjs
@@ -51,7 +51,13 @@ class InvertImage extends Operation {
             if (ENVIRONMENT_IS_WORKER())
                 self.sendStatusMessage("Inverting image...");
             image.invert();
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error inverting image. (${err})`);
diff --git a/src/core/operations/NormaliseImage.mjs b/src/core/operations/NormaliseImage.mjs
index bb5113a7..c49cc977 100644
--- a/src/core/operations/NormaliseImage.mjs
+++ b/src/core/operations/NormaliseImage.mjs
@@ -41,12 +41,26 @@ class NormaliseImage extends Operation {
             throw new OperationError("Invalid file type.");
         }
 
-        const image = await jimp.read(Buffer.from(input));
+        let image;
+        try {
+            image = await jimp.read(Buffer.from(input));
+        } catch (err) {
+            throw new OperationError(`Error opening image file. (${err})`);
+        }
 
-        image.normalize();
+        try {
+            image.normalize();
 
-        const imageBuffer = await image.getBufferAsync(jimp.AUTO);
-        return [...imageBuffer];
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
+            return [...imageBuffer];
+        } catch (err) {
+            throw new OperationError(`Error normalising image. (${err})`);
+        }
     }
 
     /**
diff --git a/src/core/operations/ResizeImage.mjs b/src/core/operations/ResizeImage.mjs
index 48a5d54a..11266ba8 100644
--- a/src/core/operations/ResizeImage.mjs
+++ b/src/core/operations/ResizeImage.mjs
@@ -110,7 +110,12 @@ class ResizeImage extends Operation {
                 image.resize(width, height, resizeMap[resizeAlg]);
             }
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error resizing image. (${err})`);
diff --git a/src/core/operations/RotateImage.mjs b/src/core/operations/RotateImage.mjs
index 34497863..16330c44 100644
--- a/src/core/operations/RotateImage.mjs
+++ b/src/core/operations/RotateImage.mjs
@@ -59,7 +59,13 @@ class RotateImage extends Operation {
             if (ENVIRONMENT_IS_WORKER())
                 self.sendStatusMessage("Rotating image...");
             image.rotate(degrees);
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error rotating image. (${err})`);
diff --git a/src/core/operations/SharpenImage.mjs b/src/core/operations/SharpenImage.mjs
index 3ef1912e..de2f3603 100644
--- a/src/core/operations/SharpenImage.mjs
+++ b/src/core/operations/SharpenImage.mjs
@@ -134,7 +134,12 @@ class SharpenImage extends Operation {
                 }
             });
 
-            const imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            let imageBuffer;
+            if (image.getMIME() === "image/gif") {
+                imageBuffer = await image.getBufferAsync(jimp.MIME_PNG);
+            } else {
+                imageBuffer = await image.getBufferAsync(jimp.AUTO);
+            }
             return [...imageBuffer];
         } catch (err) {
             throw new OperationError(`Error sharpening image. (${err})`);