diff --git a/semver_tests/src/test_cases/enum_repr_int_changed.rs b/semver_tests/src/test_cases/enum_repr_int_changed.rs
index 9bc8d9dc..e377fb0e 100644
--- a/semver_tests/src/test_cases/enum_repr_int_changed.rs
+++ b/semver_tests/src/test_cases/enum_repr_int_changed.rs
@@ -40,6 +40,20 @@ pub enum I32ToU32Enum {
     Baz,
 }
 
+#[cfg(not(feature = "enum_repr_int_changed"))]
+#[repr(isize)]
+pub enum IsizeToUsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(feature = "enum_repr_int_changed")]
+#[repr(usize)]
+pub enum IsizeToUsizeEnum {
+    Bar,
+    Baz,
+}
+
 // The following enums have *removals* of repr(i*) and repr(u*),
 // not changes to another repr(i*) or repr(u*).
 // They should not be reported by this rule, because they have their own rule.
@@ -69,3 +83,29 @@ pub enum I32Enum {
     Bar,
     Baz,
 }
+
+#[cfg(not(feature = "enum_repr_int_changed"))]
+#[repr(isize)]
+pub enum IsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(feature = "enum_repr_int_changed")]
+pub enum IsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(not(feature = "enum_repr_int_changed"))]
+#[repr(usize)]
+pub enum UsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(feature = "enum_repr_int_changed")]
+pub enum UsizeEnum {
+    Bar,
+    Baz,
+}
diff --git a/semver_tests/src/test_cases/enum_repr_int_removed.rs b/semver_tests/src/test_cases/enum_repr_int_removed.rs
index 6cb0585d..d2297f0d 100644
--- a/semver_tests/src/test_cases/enum_repr_int_removed.rs
+++ b/semver_tests/src/test_cases/enum_repr_int_removed.rs
@@ -23,3 +23,29 @@ pub enum I32Enum {
     Bar,
     Baz,
 }
+
+#[cfg(not(feature = "enum_repr_int_removed"))]
+#[repr(isize)]
+pub enum IsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(feature = "enum_repr_int_removed")]
+pub enum IsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(not(feature = "enum_repr_int_removed"))]
+#[repr(usize)]
+pub enum UsizeEnum {
+    Bar,
+    Baz,
+}
+
+#[cfg(feature = "enum_repr_int_removed")]
+pub enum UsizeEnum {
+    Bar,
+    Baz,
+}
diff --git a/src/queries/enum_repr_int_changed.ron b/src/queries/enum_repr_int_changed.ron
index a940002e..fe242fe3 100644
--- a/src/queries/enum_repr_int_changed.ron
+++ b/src/queries/enum_repr_int_changed.ron
@@ -58,7 +58,7 @@ SemverQuery(
     }"#,
     arguments: {
         "public": "public",
-        "repr_regex": "#\\[repr\\([ui]\\d+\\)\\]",
+        "repr_regex": "#\\[repr\\([ui]\\d+|size\\)\\]",
         "zero": 0,
     },
     error_message: "The repr(u*) or repr(i*) attribute on an enum was changed to another integer type. This can cause its memory representation to change, breaking FFI use cases.",
diff --git a/src/queries/enum_repr_int_removed.ron b/src/queries/enum_repr_int_removed.ron
index 5a3c658f..c9fc037f 100644
--- a/src/queries/enum_repr_int_removed.ron
+++ b/src/queries/enum_repr_int_removed.ron
@@ -51,7 +51,7 @@ SemverQuery(
     }"#,
     arguments: {
         "public": "public",
-        "repr_regex": "#\\[repr\\([ui]\\d+\\)\\]",
+        "repr_regex": "#\\[repr\\([ui]\\d+|size\\)\\]",
         "zero": 0,
     },
     error_message: "repr(u*) or repr(i*) was removed from an enum. This can cause its memory representation to change, breaking FFI use cases.",
diff --git a/src/test_data/enum_repr_int_changed.output.ron b/src/test_data/enum_repr_int_changed.output.ron
index c8a8909c..78dee462 100644
--- a/src/test_data/enum_repr_int_changed.output.ron
+++ b/src/test_data/enum_repr_int_changed.output.ron
@@ -46,5 +46,21 @@
             String("#[repr(u32)]"),
         ]),
         "visibility_limit": String("public"),
+    },
+    {
+        "name": String("IsizeToUsizeEnum"),
+        "path": List([
+            String("semver_tests"),
+            String("test_cases"),
+            String("enum_repr_int_changed"),
+            String("IsizeToUsizeEnum"),
+        ]),
+        "span_filename": String("src/test_cases/enum_repr_int_changed.rs"),
+        "span_begin_line": Uint64(52),
+        "old_attr": String("#[repr(isize)]"),
+        "new_attr": List([
+            String("#[repr(usize)]"),
+        ]),
+        "visibility_limit": String("public"),
     }
 ]
diff --git a/src/test_data/enum_repr_int_removed.output.ron b/src/test_data/enum_repr_int_removed.output.ron
index 53cf128e..f1d6d762 100644
--- a/src/test_data/enum_repr_int_removed.output.ron
+++ b/src/test_data/enum_repr_int_removed.output.ron
@@ -22,5 +22,29 @@
         "span_filename": String("src/test_cases/enum_repr_int_removed.rs"),
         "span_begin_line": Uint64(22),
         "visibility_limit": String("public"),
+    },
+    {
+        "name": String("IsizeEnum"),
+        "path": List([
+            String("semver_tests"),
+            String("test_cases"),
+            String("enum_repr_int_removed"),
+            String("IsizeEnum"),
+        ]),
+        "span_filename": String("src/test_cases/enum_repr_int_removed.rs"),
+        "span_begin_line": Uint64(35),
+        "visibility_limit": String("public"),
+    },
+    {
+        "name": String("UsizeEnum"),
+        "path": List([
+            String("semver_tests"),
+            String("test_cases"),
+            String("enum_repr_int_removed"),
+            String("UsizeEnum"),
+        ]),
+        "span_filename": String("src/test_cases/enum_repr_int_removed.rs"),
+        "span_begin_line": Uint64(48),
+        "visibility_limit": String("public"),
     }
 ]