diff --git a/apps/backend-e2e/files/map_nozip.bsp b/apps/backend-e2e/files/map_nozip.bsp
new file mode 100644
index 000000000..87f3f2c8e
Binary files /dev/null and b/apps/backend-e2e/files/map_nozip.bsp differ
diff --git a/apps/backend-e2e/src/maps.e2e-spec.ts b/apps/backend-e2e/src/maps.e2e-spec.ts
index 21d0fec30..02bc080f8 100644
--- a/apps/backend-e2e/src/maps.e2e-spec.ts
+++ b/apps/backend-e2e/src/maps.e2e-spec.ts
@@ -506,6 +506,7 @@ describe('Maps', () => {
         u2,
         u3,
         bspBuffer,
+        nozipBspBuffer,
         bspHash,
         vmfBuffer,
         vmfHash;
@@ -519,6 +520,8 @@ describe('Maps', () => {
         bspBuffer = readFileSync(path.join(FILES_PATH, 'map.bsp'));
         bspHash = createSha1Hash(bspBuffer);
 
+        nozipBspBuffer = readFileSync(path.join(FILES_PATH, 'map_nozip.bsp'));
+
         vmfBuffer = readFileSync(path.join(FILES_PATH, 'map.vmf'));
         vmfHash = createSha1Hash(vmfBuffer);
 
@@ -976,6 +979,36 @@ describe('Maps', () => {
           });
         });
 
+        it('should 400 if a BSP file has invalid header', async () => {
+          await req.postAttach({
+            url: 'maps',
+            status: 400,
+            data: createMapObject,
+            files: [
+              {
+                file: Buffer.alloc(100),
+                field: 'bsp',
+                fileName: 'surf_map.bsp'
+              },
+              { file: vmfBuffer, field: 'vmfs', fileName: 'surf_map.vmf' }
+            ],
+            token
+          });
+        });
+
+        it('should 400 if a BSP file was not compressed', async () => {
+          await req.postAttach({
+            url: 'maps',
+            status: 400,
+            data: createMapObject,
+            files: [
+              { file: nozipBspBuffer, field: 'bsp', fileName: 'surf_map.bsp' },
+              { file: vmfBuffer, field: 'vmfs', fileName: 'surf_map.vmf' }
+            ],
+            token
+          });
+        });
+
         it('should succeed if VMF file is missing', async () =>
           req.postAttach({
             url: 'maps',
diff --git a/apps/backend/src/app/modules/maps/maps.service.ts b/apps/backend/src/app/modules/maps/maps.service.ts
index 5c149655d..8573380df 100644
--- a/apps/backend/src/app/modules/maps/maps.service.ts
+++ b/apps/backend/src/app/modules/maps/maps.service.ts
@@ -88,6 +88,7 @@ import {
   LeaderboardHandler,
   LeaderboardProps
 } from './leaderboard-handler.util';
+import { BspHeader, BspReadError } from '@momentum/formats/bsp';
 
 @Injectable()
 export class MapsService {
@@ -538,6 +539,9 @@ export class MapsService {
     vmfFiles?: File[]
   ): Promise<MapDto> {
     await this.checkCreateDto(userID, dto);
+
+    await this.checkMapCompression(bspFile);
+
     this.checkMapFiles(dto.fileName, bspFile, vmfFiles);
     this.checkMapFileNames(dto.name, dto.fileName);
 
@@ -634,6 +638,8 @@ export class MapsService {
       throw new ForbiddenException('Map does not allow editing');
     }
 
+    await this.checkMapCompression(bspFile);
+
     this.checkMapFiles(map.fileName, bspFile, vmfFiles);
 
     const hasVmf = vmfFiles?.length > 0;
@@ -1674,6 +1680,25 @@ export class MapsService {
     }
   }
 
+  /**
+   * Check if provided bsp file was compressed with bspzip
+   * @throws BadRequestException
+   */
+  async checkMapCompression(bspFile: File) {
+    const header = await BspHeader.fromBlob(new Blob([bspFile.buffer])).catch(
+      (error) => {
+        throw new BadRequestException(
+          error instanceof BspReadError
+            ? error.message
+            : 'Unknown error reading BSP file'
+        );
+      }
+    );
+
+    if (!header.isCompressed())
+      throw new BadRequestException('BSP is not compressed');
+  }
+
   //#endregion
 }