diff --git a/.changeset/modern-students-poke.md b/.changeset/modern-students-poke.md
new file mode 100644
index 00000000000..252bea9a57f
--- /dev/null
+++ b/.changeset/modern-students-poke.md
@@ -0,0 +1,5 @@
+---
+"@fuel-ts/abi-coder": patch
+---
+
+fix: `enum` size validation
diff --git a/.github/workflows/pr-release.yaml b/.github/workflows/pr-release.yaml
index 6cc274cba00..6eeca1f3f04 100644
--- a/.github/workflows/pr-release.yaml
+++ b/.github/workflows/pr-release.yaml
@@ -36,4 +36,4 @@ jobs:
           message: |
             This PR is published in NPM with version **${{ steps.release.outputs.published_version }}**
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
\ No newline at end of file
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/packages/abi-coder/src/encoding/coders/EnumCoder.ts b/packages/abi-coder/src/encoding/coders/EnumCoder.ts
index 4fe2b1fbe40..f27f0d3b6e3 100644
--- a/packages/abi-coder/src/encoding/coders/EnumCoder.ts
+++ b/packages/abi-coder/src/encoding/coders/EnumCoder.ts
@@ -3,7 +3,7 @@ import { toNumber } from '@fuel-ts/math';
 import { concat } from '@fuel-ts/utils';
 import type { RequireExactlyOne } from 'type-fest';
 
-import { OPTION_CODER_TYPE, WORD_SIZE } from '../../utils/constants';
+import { OPTION_CODER_TYPE } from '../../utils/constants';
 import { hasNestedOption } from '../../utils/utilities';
 
 import type { TypesOfCoder } from './AbstractCoder';
@@ -36,7 +36,7 @@ export class EnumCoder<TCoders extends Record<string, Coder>> extends Coder<
   constructor(name: string, coders: TCoders) {
     const caseIndexCoder = new BigNumberCoder('u64');
     const encodedValueSize = Object.values(coders).reduce(
-      (max, coder) => Math.max(max, coder.encodedLength),
+      (min, coder) => Math.min(min, coder.encodedLength),
       0
     );
     super(`enum ${name}`, `enum ${name}`, caseIndexCoder.encodedLength + encodedValueSize);
@@ -80,7 +80,7 @@ export class EnumCoder<TCoders extends Record<string, Coder>> extends Coder<
   }
 
   decode(data: Uint8Array, offset: number): [DecodedValueOf<TCoders>, number] {
-    if (this.#shouldValidateLength && data.length < this.#encodedValueSize) {
+    if (this.#shouldValidateLength && data.length < this.encodedLength) {
       throw new FuelError(ErrorCode.DECODE_ERROR, `Invalid enum data size.`);
     }
 
@@ -93,9 +93,12 @@ export class EnumCoder<TCoders extends Record<string, Coder>> extends Coder<
         `Invalid caseIndex "${caseIndex}". Valid cases: ${Object.keys(this.coders)}.`
       );
     }
-
     const valueCoder = this.coders[caseKey];
-    const offsetAndCase = offset + WORD_SIZE;
+    const offsetAndCase = offset + this.#caseIndexCoder.encodedLength;
+
+    if (this.#shouldValidateLength && data.length < offsetAndCase + valueCoder.encodedLength) {
+      throw new FuelError(ErrorCode.DECODE_ERROR, `Invalid enum data size.`);
+    }
 
     const [decoded, newOffset] = valueCoder.decode(data, offsetAndCase);
 
diff --git a/packages/fuel-gauge/src/options.test.ts b/packages/fuel-gauge/src/options.test.ts
index 7d00d5380e1..548e3214db4 100644
--- a/packages/fuel-gauge/src/options.test.ts
+++ b/packages/fuel-gauge/src/options.test.ts
@@ -192,4 +192,26 @@ describe('Options Tests', () => {
 
     expect(value).toStrictEqual(undefined);
   });
+
+  it('echoes option enum diff sizes', async () => {
+    const { value } = await contractInstance.functions.echo_enum_diff_sizes(undefined).call();
+
+    expect(value).toStrictEqual(undefined);
+
+    const { value: value2 } = await contractInstance.functions
+      .echo_enum_diff_sizes({ a: U8_MAX })
+      .call();
+
+    expect(value2).toStrictEqual({ a: U8_MAX });
+
+    const { value: value3 } = await contractInstance.functions
+      .echo_enum_diff_sizes({
+        b: '0x9ae5b658754e096e4d681c548daf46354495a437cc61492599e33fc64dcdc30c',
+      })
+      .call();
+
+    expect(value3).toStrictEqual({
+      b: '0x9ae5b658754e096e4d681c548daf46354495a437cc61492599e33fc64dcdc30c',
+    });
+  });
 });
diff --git a/packages/fuel-gauge/test/fixtures/forc-projects/options/src/main.sw b/packages/fuel-gauge/test/fixtures/forc-projects/options/src/main.sw
index 883e6d074c5..95cfda5a5ae 100644
--- a/packages/fuel-gauge/test/fixtures/forc-projects/options/src/main.sw
+++ b/packages/fuel-gauge/test/fixtures/forc-projects/options/src/main.sw
@@ -56,6 +56,11 @@ struct SomeStruct {
     b: u64,
 }
 
+enum DiffSizeEnum {
+    a: u8,
+    b: b256,
+}
+
 storage {
     stuff: StorageMap<Identity, SomeStruct> = StorageMap {},
 }
@@ -71,6 +76,7 @@ abi OptionContract {
     fn echo_array_option(arg: [Option<u16>; 3]) -> [Option<u16>; 3];
     fn print_enum_option_array() -> GardenVector;
     fn echo_deeply_nested_option(arg: DeepStruct) -> DeepStruct;
+    fn echo_enum_diff_sizes(arg: Option<DiffSizeEnum>) -> Option<DiffSizeEnum>;
 }
 
 impl OptionContract for Contract {
@@ -110,4 +116,8 @@ impl OptionContract for Contract {
     fn echo_deeply_nested_option(arg: DeepStruct) -> DeepStruct {
         arg
     }
+
+    fn echo_enum_diff_sizes(arg: Option<DiffSizeEnum>) -> Option<DiffSizeEnum> {
+        arg
+    }
 }