diff --git a/libaegisub/common/util.cpp b/libaegisub/common/util.cpp
index 8f96b4715..765e759c0 100644
--- a/libaegisub/common/util.cpp
+++ b/libaegisub/common/util.cpp
@@ -137,7 +137,7 @@ std::pair<size_t, size_t> ifind(std::string const& haystack, std::string const&
 
 #ifndef __APPLE__
 namespace osx {
-AppNapDisabler::AppNapDisabler(std::string const& reason) { }
+AppNapDisabler::AppNapDisabler(std::string reason) { }
 AppNapDisabler::~AppNapDisabler() { }
 }
 #endif
diff --git a/libaegisub/include/libaegisub/util_osx.h b/libaegisub/include/libaegisub/util_osx.h
index 7fcd6d1b3..cc9ec21c7 100644
--- a/libaegisub/include/libaegisub/util_osx.h
+++ b/libaegisub/include/libaegisub/util_osx.h
@@ -35,7 +35,7 @@ namespace agi {
 		class AppNapDisabler {
 			void *handle;
 		public:
-			AppNapDisabler(std::string const& reason);
+			AppNapDisabler(std::string reason);
 			~AppNapDisabler();
 		};
 	}
diff --git a/libaegisub/osx/util.mm b/libaegisub/osx/util.mm
index f2837a997..0e1206f4c 100644
--- a/libaegisub/osx/util.mm
+++ b/libaegisub/osx/util.mm
@@ -29,7 +29,8 @@ static std::string EmptyIfNil(NSString *string) {
 
 namespace agi {
 	namespace osx {
-AppNapDisabler::AppNapDisabler(std::string const& reason) : handle(nullptr) {
+AppNapDisabler::AppNapDisabler(std::string reason) : handle(nullptr) {
+	if (reason.empty()) reason = "Loading";
 	auto processInfo = [NSProcessInfo processInfo];
 	if ([processInfo respondsToSelector:@selector(beginActivityWithOptions:reason:)])
 		handle = [[processInfo beginActivityWithOptions:NSActivityUserInitiatedAllowingIdleSystemSleep