diff --git a/Telegram/SourceFiles/base/assertion.h b/Telegram/SourceFiles/base/assertion.h
index 1711e1504..cd638d563 100644
--- a/Telegram/SourceFiles/base/assertion.h
+++ b/Telegram/SourceFiles/base/assertion.h
@@ -30,6 +30,8 @@ void log(const char *message, const char *file, int line);
 
 // Release build assertions.
 inline constexpr void noop() {
+  // MSVC2015 requires return to suppress warning: a constexpr function must contain exactly one return statement
+  return void();
 }
 
 [[noreturn]] inline void fail(const char *message, const char *file, int line) {
@@ -43,14 +45,9 @@ inline constexpr void noop() {
 	std::abort();
 }
 
-// Since MSVC 2015 cannot understand "constexpr void" (void is literal since C++14)
-// we have to use conditional compilation 
-inline
-#if !defined(_MSC_VER) || (_MSC_VER > 1900)
-constexpr
-#endif
-  void validate(bool condition, const char *message, const char *file, int line) {
-	(GSL_UNLIKELY(!(condition))) ? fail(message, file, line) : noop();
+inline constexpr void validate(bool condition, const char *message, const char *file, int line) {
+  // MSVC2015 requires return to suppress error C3249: illegal statement or sub-expression for 'constexpr' function
+  return (GSL_UNLIKELY(!(condition))) ? fail(message, file, line) : noop();
 }