diff --git a/test/core/custom-page-sizes/custom-page-sizes-invalid.wast b/test/core/custom-page-sizes/custom-page-sizes-invalid.wast
index 80cbcff..480d385 100644
--- a/test/core/custom-page-sizes/custom-page-sizes-invalid.wast
+++ b/test/core/custom-page-sizes/custom-page-sizes-invalid.wast
@@ -4,6 +4,11 @@
   "invalid custom page size"
 )
 
+(assert_malformed
+  (module quote "(memory 0 (pagesize 0))")
+  "invalid custom page size"
+)
+
 ;; Power-of-two page sizes that are not 1 or 64KiB.
 (assert_invalid
   (module (memory 0 (pagesize 2)))
diff --git a/test/core/custom-page-sizes/custom-page-sizes.wast b/test/core/custom-page-sizes/custom-page-sizes.wast
index b312f1f..e7e8b68 100644
--- a/test/core/custom-page-sizes/custom-page-sizes.wast
+++ b/test/core/custom-page-sizes/custom-page-sizes.wast
@@ -106,3 +106,33 @@
 (module
   (memory (import "m" "large-pages-memory") 0 (pagesize 65536))
 )
+
+;; Inline data segments
+
+;; pagesize 0
+(assert_malformed (module quote "(memory (pagesize 0) (data))") "invalid custom page size")
+
+;; pagesize 1
+(module
+  (memory (pagesize 1) (data "xyz"))
+  (func (export "size") (result i32)
+    memory.size)
+  (func (export "grow") (param i32) (result i32)
+    (memory.grow (local.get 0)))
+  (func (export "load") (param i32) (result i32)
+    (i32.load8_u (local.get 0))))
+
+(assert_return (invoke "size") (i32.const 3))
+(assert_return (invoke "load" (i32.const 0)) (i32.const 120))
+(assert_return (invoke "load" (i32.const 1)) (i32.const 121))
+(assert_return (invoke "load" (i32.const 2)) (i32.const 122))
+(assert_trap (invoke "load" (i32.const 3)) "out of bounds")
+(assert_return (invoke "grow" (i32.const 1)) (i32.const -1))
+
+;; pagesize 65536
+(module
+  (memory (pagesize 65536) (data "xyz"))
+  (func (export "size") (result i32)
+        memory.size))
+
+(assert_return (invoke "size") (i32.const 1))
diff --git a/test/core/custom-page-sizes/memory_max.wast b/test/core/custom-page-sizes/memory_max.wast
new file mode 100644
index 0000000..7e0fdc0
--- /dev/null
+++ b/test/core/custom-page-sizes/memory_max.wast
@@ -0,0 +1,64 @@
+;; Maximum memory sizes.
+;;
+;; These modules are valid, but instantiating them is unnecessary
+;; and would only allocate very large memories and slow down running
+;; the spec tests. Therefore, add a missing import so that it cannot
+;; be instantiated and use `assert_unlinkable`. This approach
+;; enforces that the module itself is still valid, but that its
+;; instantiation fails early (hopefully before any memories are
+;; actually allocated).
+
+;; i32 (pagesize 1)
+(assert_unlinkable
+  (module
+    (import "test" "unknown" (func))
+    (memory 0xFFFF_FFFF (pagesize 1)))
+  "unknown import")
+
+;; i64 (pagesize 1)
+(assert_unlinkable
+  (module
+    (import "test" "import" (func))
+    (memory i64 0xFFFF_FFFF_FFFF_FFFF (pagesize 1)))
+  "unknown import")
+
+;; i32 (default pagesize)
+(assert_unlinkable
+  (module
+    (import "test" "unknown" (func))
+    (memory 65536 (pagesize 65536)))
+  "unknown import")
+
+;; i64 (default pagesize)
+(assert_unlinkable
+  (module
+    (import "test" "unknown" (func))
+    (memory i64 0x1_0000_0000_0000 (pagesize 65536)))
+  "unknown import")
+
+;; Memory size just over the maximum.
+;;
+;; These are malformed (for pagesize 1)
+;; or invalid (for other pagesizes).
+
+;; i32 (pagesize 1)
+(assert_malformed
+  (module quote "(memory 0x1_0000_0000 (pagesize 1))")
+  "constant out of range")
+
+;; i64 (pagesize 1)
+(assert_malformed
+  (module quote "(memory i64 0x1_0000_0000_0000_0000 (pagesize 1))")
+  "constant out of range")
+
+;; i32 (default pagesize)
+(assert_invalid
+  (module
+    (memory 65537 (pagesize 65536)))
+  "memory size must be at most")
+
+;; i64 (default pagesize)
+(assert_invalid
+  (module
+    (memory i64 0x1_0000_0000_0001 (pagesize 65536)))
+  "memory size must be at most")