diff --git a/dlls/mshtml/tests/dom.c b/dlls/mshtml/tests/dom.c
index 88eddc511a9..36946808f89 100644
--- a/dlls/mshtml/tests/dom.c
+++ b/dlls/mshtml/tests/dom.c
@@ -4162,7 +4162,7 @@ static void gecko_installer_workaround(BOOL disable)
 
 /* Check if Internet Explorer is configured to run in "Enhanced Security Configuration" (aka hardened mode) */
 /* Note: this code is duplicated in dlls/mshtml/tests/dom.c, dlls/mshtml/tests/script.c and dlls/urlmon/tests/misc.c */
-static BOOL is_ie_hardened()
+static BOOL is_ie_hardened(void)
 {
     HKEY zone_map;
     DWORD ie_harden, type, size;
diff --git a/dlls/mshtml/tests/script.c b/dlls/mshtml/tests/script.c
index 30be52cefbc..6178cdf3fc9 100644
--- a/dlls/mshtml/tests/script.c
+++ b/dlls/mshtml/tests/script.c
@@ -1139,7 +1139,7 @@ static void gecko_installer_workaround(BOOL disable)
 
 /* Check if Internet Explorer is configured to run in "Enhanced Security Configuration" (aka hardened mode) */
 /* Note: this code is duplicated in dlls/mshtml/tests/dom.c, dlls/mshtml/tests/script.c and dlls/urlmon/tests/misc.c */
-static BOOL is_ie_hardened()
+static BOOL is_ie_hardened(void)
 {
     HKEY zone_map;
     DWORD ie_harden, type, size;