diff --git a/include/SDL3/SDL_assert.h b/include/SDL3/SDL_assert.h
index 6560d197d3..e65836a0dd 100644
--- a/include/SDL3/SDL_assert.h
+++ b/include/SDL3/SDL_assert.h
@@ -232,11 +232,16 @@ extern "C" {
 #define SDL_LINE    __LINE__
 
 /*
-sizeof (x) makes the compiler still parse the expression even without
-assertions enabled, so the code is always checked at compile time, but
+sizeof ((x) ? 1 : 0) makes the compiler still parse the expression even
+without assertions enabled, so the code is always checked at compile time, but
 doesn't actually generate code for it, so there are no side effects or
-expensive checks at run time, just the constant size of what x WOULD be,
+expensive checks at run time, just the constant size of what int would be,
 which presumably gets optimized out as unused.
+
+(The `? 1 : 0` is so this always dithers down to `sizeof (int)`...otherwise
+you'll have problems when bitfields are used as the condition, since the
+compiler will error out on the sizeof.)
+
 This also solves the problem of...
 
     int somevalue = blah();
@@ -284,14 +289,14 @@ disable assertions.
  *
  * The code does nothing, but wraps `condition` in a sizeof operator, which
  * generates no code and has no side effects, but avoid compiler warnings
- * about unused variables.
+ * about unused variables, and still checks syntax even when disabled.
  *
  * \param condition the condition to assert (but not actually run here).
  *
  * \since This macro is available since SDL 3.2.0.
  */
 #define SDL_disabled_assert(condition) \
-    do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
+    do { (void) sizeof ((condition) ? 1 : 0); } while (SDL_NULL_WHILE_LOOP_CONDITION)
 
 /**
  * Possible outcomes from a triggered assertion.