diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 6f442134..3ee0e72d 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -1541,7 +1541,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > 0xff ||
         _glfw.ns.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 
diff --git a/src/win32_window.c b/src/win32_window.c
index d17b6da4..2fa4f2e1 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -2067,7 +2067,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > (KF_EXTENDED | 0xff) ||
         _glfw.win32.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 
diff --git a/src/x11_window.c b/src/x11_window.c
index d52ebc4d..e5333d4e 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -2886,7 +2886,7 @@ const char* _glfwPlatformGetScancodeName(int scancode)
     if (scancode < 0 || scancode > 0xff ||
         _glfw.x11.keycodes[scancode] == GLFW_KEY_UNKNOWN)
     {
-        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode");
+        _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }