diff --git a/include/pocketpy/common/linalg.h b/include/pocketpy/common/linalg.h
new file mode 100644
index 00000000..e8fabf9f
--- /dev/null
+++ b/include/pocketpy/common/linalg.h
@@ -0,0 +1,35 @@
+#pragma once
+
+typedef struct c11_vec2i {
+    int x;
+    int y;
+} c11_vec2i;
+
+typedef struct c11_vec3i {
+    int x;
+    int y;
+    int z;
+} c11_vec3i;
+
+typedef struct c11_vec2 {
+    float x;
+    float y;
+} c11_vec2;
+
+typedef struct c11_vec3 {
+    float x;
+    float y;
+    float z;
+} c11_vec3;
+
+typedef struct c11_mat3x3 {
+    union {
+        struct {
+            float _11, _12, _13;
+            float _21, _22, _23;
+            float _31, _32, _33;
+        };
+        float m[3][3];
+        float v[9];
+    };
+} c11_mat3x3;