diff --git a/core/Controller/CssController.php b/core/Controller/CssController.php
index b467d386f98c0..57197e9999e5e 100644
--- a/core/Controller/CssController.php
+++ b/core/Controller/CssController.php
@@ -95,7 +95,7 @@ private function getFile(ISimpleFolder $folder, $fileName, &$gzip) {
 		if ($encoding !== null && strpos($encoding, 'gzip') !== false) {
 			try {
 				$gzip = true;
-				return $folder->getFile($fileName . '.gz');
+				return $folder->getFile($fileName . '.gzip'); # Safari doesn't like .gz
 			} catch (NotFoundException $e) {
 				// continue
 			}
diff --git a/core/Controller/JsController.php b/core/Controller/JsController.php
index 0b50abc158ad3..c7c9dea910168 100644
--- a/core/Controller/JsController.php
+++ b/core/Controller/JsController.php
@@ -96,7 +96,7 @@ private function getFile(ISimpleFolder $folder, $fileName, &$gzip) {
 		if ($encoding !== null && strpos($encoding, 'gzip') !== false) {
 			try {
 				$gzip = true;
-				return $folder->getFile($fileName . '.gz');
+				return $folder->getFile($fileName . '.gzip'); # Safari doesn't like .gz
 			} catch (NotFoundException $e) {
 				// continue
 			}
diff --git a/lib/private/Template/JSCombiner.php b/lib/private/Template/JSCombiner.php
index 0f30fb915f775..77c46a5e45e95 100644
--- a/lib/private/Template/JSCombiner.php
+++ b/lib/private/Template/JSCombiner.php
@@ -155,9 +155,9 @@ protected function cache($path, $fileName, ISimpleFolder $folder) {
 		}
 
 		try {
-			$gzipFile = $folder->getFile($fileName . '.gz');
+			$gzipFile = $folder->getFile($fileName . '.gzip'); # Safari doesn't like .gz
 		} catch (NotFoundException $e) {
-			$gzipFile = $folder->newFile($fileName . '.gz');
+			$gzipFile = $folder->newFile($fileName . '.gzip'); # Safari doesn't like .gz
 		}
 
 		try {
diff --git a/lib/private/Template/SCSSCacher.php b/lib/private/Template/SCSSCacher.php
index df2e023250886..6e09f41a215e5 100644
--- a/lib/private/Template/SCSSCacher.php
+++ b/lib/private/Template/SCSSCacher.php
@@ -188,9 +188,9 @@ private function cache($path, $fileNameCSS, $fileNameSCSS, ISimpleFolder $folder
 
 		// Gzip file
 		try {
-			$gzipFile = $folder->getFile($fileNameCSS . '.gz');
+			$gzipFile = $folder->getFile($fileNameCSS . '.gzip'); # Safari doesn't like .gz
 		} catch (NotFoundException $e) {
-			$gzipFile = $folder->newFile($fileNameCSS . '.gz');
+			$gzipFile = $folder->newFile($fileNameCSS . '.gzip'); # Safari doesn't like .gz
 		}
 
 		try {
diff --git a/tests/Core/Controller/CssControllerTest.php b/tests/Core/Controller/CssControllerTest.php
index 7fa358e056efa..30bbc12809e9b 100644
--- a/tests/Core/Controller/CssControllerTest.php
+++ b/tests/Core/Controller/CssControllerTest.php
@@ -121,7 +121,7 @@ public function testGetGzipFile() {
 			->willReturn($folder);
 
 		$folder->method('getFile')
-			->with('file.css.gz')
+			->with('file.css.gzip')
 			->willReturn($gzipFile);
 
 		$this->request->method('getHeader')
diff --git a/tests/Core/Controller/JsControllerTest.php b/tests/Core/Controller/JsControllerTest.php
index 8f48a7c339059..8456ba8b6e389 100644
--- a/tests/Core/Controller/JsControllerTest.php
+++ b/tests/Core/Controller/JsControllerTest.php
@@ -120,7 +120,7 @@ public function testGetGzipFile() {
 			->willReturn($folder);
 
 		$folder->method('getFile')
-			->with('file.js.gz')
+			->with('file.js.gzip')
 			->willReturn($gzipFile);
 
 		$this->request->method('getHeader')
diff --git a/tests/lib/Template/JSCombinerTest.php b/tests/lib/Template/JSCombinerTest.php
index 1e6234a062c93..89bb13338c829 100644
--- a/tests/lib/Template/JSCombinerTest.php
+++ b/tests/lib/Template/JSCombinerTest.php
@@ -111,7 +111,7 @@ public function testProcessUncachedFileNoAppDataFolder() {
 					return $file;
 				} else if ($path === 'combine.js.deps') {
 					throw new NotFoundException();
-				} else if ($path === 'combine.js.gz') {
+				} else if ($path === 'combine.js.gzip') {
 					return $gzfile;
 				}
 				$this->fail();
@@ -148,7 +148,7 @@ public function testProcessUncachedFile() {
 					return $file;
 				} else if ($path === 'combine.js.deps') {
 					throw new NotFoundException();
-				} else if ($path === 'combine.js.gz') {
+				} else if ($path === 'combine.js.gzip') {
 					return $gzfile;
 				}
 				$this->fail();
@@ -302,7 +302,7 @@ function ($filename) use ($file, $depsFile, $gzFile) {
 					return $file;
 				} else if ($filename === 'combine.js.deps') {
 					return $depsFile;
-				} else if ($filename === 'combine.js.gz') {
+				} else if ($filename === 'combine.js.gzip') {
 					return $gzFile;
 				}
 				$this->fail();
@@ -333,7 +333,7 @@ function ($filename) use ($file, $depsFile, $gzFile) {
 					return $file;
 				} else if ($filename === 'combine.js.deps') {
 					return $depsFile;
-				} else if ($filename === 'combine.js.gz') {
+				} else if ($filename === 'combine.js.gzip') {
 					return $gzFile;
 				}
 				$this->fail();
@@ -401,7 +401,7 @@ function ($filename) use ($file, $depsFile, $gzFile) {
 					return $file;
 				} else if ($filename === 'combine.js.deps') {
 					return $depsFile;
-				} else if ($filename === 'combine.js.gz') {
+				} else if ($filename === 'combine.js.gzip') {
 					return $gzFile;
 				}
 				$this->fail();
diff --git a/tests/lib/Template/SCSSCacherTest.php b/tests/lib/Template/SCSSCacherTest.php
index 887fa1ed605a4..24865b9ae458d 100644
--- a/tests/lib/Template/SCSSCacherTest.php
+++ b/tests/lib/Template/SCSSCacherTest.php
@@ -81,7 +81,7 @@ public function testProcessUncachedFileNoAppDataFolder() {
 					return $file;
 				} else if ($path === 'styles.css.deps') {
 					throw new NotFoundException();
-				} else if ($path === 'styles.css.gz') {
+				} else if ($path === 'styles.css.gzip') {
 					return $gzfile;
 				} else {
 					$this->fail();
@@ -110,7 +110,7 @@ public function testProcessUncachedFile() {
 					return $file;
 				} else if ($path === 'styles.css.deps') {
 					throw new NotFoundException();
-				} else if ($path === 'styles.css.gz') {
+				} else if ($path === 'styles.css.gzip') {
 					return $gzfile;
 				}else {
 					$this->fail();
@@ -228,7 +228,7 @@ public function testCacheNoFile() {
 				return $file;
 			} else if ($fileName === 'styles.css.deps') {
 				return $depsFile;
-			} else if ($fileName === 'styles.css.gz') {
+			} else if ($fileName === 'styles.css.gzip') {
 				return $gzipFile;
 			}
 			throw new \Exception();
@@ -258,7 +258,7 @@ public function testCache() {
 				return $file;
 			} else if ($fileName === 'styles.css.deps') {
 				return $depsFile;
-			} else if ($fileName === 'styles.css.gz') {
+			} else if ($fileName === 'styles.css.gzip') {
 				return $gzipFile;
 			}
 			throw new \Exception();
@@ -288,7 +288,7 @@ public function testCacheSuccess() {
 				return $file;
 			} else if ($fileName === 'styles-success.css.deps') {
 				return $depsFile;
-			} else if ($fileName === 'styles-success.css.gz') {
+			} else if ($fileName === 'styles-success.css.gzip') {
 				return $gzipFile;
 			}
 			throw new \Exception();