diff --git a/src/win32_window.c b/src/win32_window.c
index f8e7c074..e8f19c61 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -42,7 +42,7 @@
 // Surrogate-pair processing) and the unit is assigned to the argument
 // `highsurrogate`. It will be used in the next unit's processing.
 // 
-static int convertToUTF32FromUTF16(WCHAR utf16_unit, 
+static GLFWbool convertToUTF32FromUTF16(WCHAR utf16_unit, 
                                    WCHAR* highsurrogate,
                                    uint32_t* codepoint)
 {