diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index 71caac1a1f..233606b414 100644
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -380,10 +380,10 @@ LWLockShmemSize(void)
 void
 CreateLWLocks(void)
 {
-	StaticAssertExpr(LW_VAL_EXCLUSIVE > (uint32) MAX_BACKENDS,
+	StaticAssertStmt(LW_VAL_EXCLUSIVE > (uint32) MAX_BACKENDS,
 					 "MAX_BACKENDS too big for lwlock.c");
 
-	StaticAssertExpr(sizeof(LWLock) <= LWLOCK_MINIMAL_SIZE &&
+	StaticAssertStmt(sizeof(LWLock) <= LWLOCK_MINIMAL_SIZE &&
 					 sizeof(LWLock) <= LWLOCK_PADDED_SIZE,
 					 "Miscalculated LWLock padding");
 
diff --git a/src/include/c.h b/src/include/c.h
index c38ef8aed3..6b55181e0a 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -779,7 +779,7 @@ extern void ExceptionalCondition(const char *conditionName,
 #define StaticAssertStmt(condition, errmessage) \
 	do { _Static_assert(condition, errmessage); } while(0)
 #define StaticAssertExpr(condition, errmessage) \
-	({ StaticAssertStmt(condition, errmessage); true; })
+	((void) ({ StaticAssertStmt(condition, errmessage); true; }))
 #else							/* !HAVE__STATIC_ASSERT */
 #define StaticAssertStmt(condition, errmessage) \
 	((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
@@ -796,7 +796,7 @@ extern void ExceptionalCondition(const char *conditionName,
 #define StaticAssertStmt(condition, errmessage) \
 	do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
 #define StaticAssertExpr(condition, errmessage) \
-	({ StaticAssertStmt(condition, errmessage); })
+	((void) ({ StaticAssertStmt(condition, errmessage); }))
 #endif
 #endif							/* C++ */
 
@@ -817,14 +817,14 @@ extern void ExceptionalCondition(const char *conditionName,
 	StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
 	CppAsString(varname) " does not have type " CppAsString(typename))
 #define AssertVariableIsOfTypeMacro(varname, typename) \
-	((void) StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
+	(StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
 	 CppAsString(varname) " does not have type " CppAsString(typename)))
 #else							/* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
 #define AssertVariableIsOfType(varname, typename) \
 	StaticAssertStmt(sizeof(varname) == sizeof(typename), \
 	CppAsString(varname) " does not have type " CppAsString(typename))
 #define AssertVariableIsOfTypeMacro(varname, typename) \
-	((void) StaticAssertExpr(sizeof(varname) == sizeof(typename),		\
+	(StaticAssertExpr(sizeof(varname) == sizeof(typename), \
 	 CppAsString(varname) " does not have type " CppAsString(typename)))
 #endif							/* HAVE__BUILTIN_TYPES_COMPATIBLE_P */