diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f418431d..a0aa5f54 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -141,4 +141,5 @@ jobs:
       - name: Run cppcheck
         shell: bash
         run: |
-          cppcheck --version ; cppcheck --error-exitcode=1 -j4 -q --force -U_WIN32 -Isrc opl src setup textscreen
+          cppcheck --version
+          cppcheck --error-exitcode=1 -j4 -q --force -D__GNUC__ -U_MSC_VER -U_WIN32 -Isrc opl src setup textscreen
diff --git a/src/g_game.c b/src/g_game.c
index 08492a19..eb956857 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -294,7 +294,7 @@ static int G_NextWeapon(int direction)
 
     if (i == arrlen(weapon_order_table))
     {
-        return wp_nochange;
+        I_Error("G_NextWeapon: Invalid weapon type %d", (int)weapon);
     }
 
     // Switch weapon. Don't loop forever.
diff --git a/src/i_system.h b/src/i_system.h
index 3057a340..2e95dd97 100644
--- a/src/i_system.h
+++ b/src/i_system.h
@@ -60,7 +60,7 @@ ticcmd_t* I_BaseTiccmd (void);
 
 // killough 3/20/98: add const
 // killough 4/25/98: add gcc attributes
-void I_ErrorOrSuccess(int err_code, const char *error, ...) PRINTF_ATTR(2, 3);
+void I_ErrorOrSuccess(int err_code, const char *error, ...) NORETURN PRINTF_ATTR(2, 3);
 #define I_Error(...) I_ErrorOrSuccess(-1, __VA_ARGS__)
 #define I_Success(...) I_ErrorOrSuccess(0, __VA_ARGS__)