diff --git a/ext/zip/php_zip.c b/ext/zip/php_zip.c
index f7cfcee57c1..43d8d27d564 100644
--- a/ext/zip/php_zip.c
+++ b/ext/zip/php_zip.c
@@ -105,8 +105,8 @@ static char * php_zip_make_relative_path(char *path, size_t path_len) /* {{{ */
 			return path;
 		}
 
-		if (i >= 2 && (path[i -1] == '.' || path[i -1] == ':')) {
-			/* i is the position of . or :, add 1 for / */
+		if (i >= 2 && path[i -1] == '.') {
+			/* i is the position of ., add 1 for / */
 			path_begin = path + i + 1;
 			break;
 		}
diff --git a/ext/zip/tests/bug77978.phpt b/ext/zip/tests/bug77978.phpt
new file mode 100644
index 00000000000..2f3c22f4213
--- /dev/null
+++ b/ext/zip/tests/bug77978.phpt
@@ -0,0 +1,37 @@
+--TEST--
+Bug #77978 (Dirname ending in colon unzips to wrong dir)
+--SKIPIF--
+<?php
+if (!extension_loaded("zip")) die("skip zip extension not available");
+?>
+--FILE--
+<?php
+$file = __DIR__ . "/bug77978.zip";
+$target = __DIR__ . "/bug77978";
+
+mkdir($target);
+
+$zip = new ZipArchive();
+$zip->open($file, ZipArchive::CREATE|ZipArchive::OVERWRITE);
+$zip->addFromString("dir/test:/filename.txt", "contents");
+$zip->close();
+
+$zip->open($file);
+// Windows won't extract filenames with colons; we suppress the warning
+@$zip->extractTo($target, "dir/test:/filename.txt");
+$zip->close();
+
+var_dump(!file_exists("$target/filename.txt"));
+var_dump(PHP_OS_FAMILY === "Windows" || file_exists("$target/dir/test:/filename.txt"));
+?>
+--EXPECT--
+bool(true)
+bool(true)
+--CLEAN--
+<?php
+@unlink(__DIR__ . "/bug77978.zip");
+@unlink(__DIR__ . "/bug77978/dir/test:/filename.txt");
+@rmdir(__DIR__ . "/bug77978/dir/test:");
+@rmdir(__DIR__ . "/bug77978/dir");
+@rmdir(__DIR__ . "/bug77978");
+?>