diff --git a/src/common.h b/src/common.h
index c5aa6700..42b8bbae 100644
--- a/src/common.h
+++ b/src/common.h
@@ -231,20 +231,6 @@ typedef struct {
   bool invert_color : 1;
 } win_upd_t;
 
-/// Structure representing Window property value.
-typedef struct winprop {
-  union {
-    void *ptr;
-    char *p8;
-    short *p16;
-    long *p32;
-    unsigned long *c32; // 32bit cardinal
-  };
-  unsigned long nitems;
-  Atom type;
-  int format;
-} winprop_t;
-
 typedef struct _ignore {
   struct _ignore *next;
   unsigned long sequence;
@@ -1584,19 +1570,6 @@ wid_has_prop(const session_t *ps, Window w, Atom atom) {
   return false;
 }
 
-winprop_t
-wid_get_prop_adv(const session_t *ps, Window w, Atom atom, long offset,
-    long length, Atom rtype, int rformat);
-
-/**
- * Wrapper of wid_get_prop_adv().
- */
-static inline winprop_t
-wid_get_prop(const session_t *ps, Window wid, Atom atom, long length,
-    Atom rtype, int rformat) {
-  return wid_get_prop_adv(ps, wid, atom, 0L, length, rtype, rformat);
-}
-
 /**
  * Get the numeric property value from a win_prop_t.
  */
diff --git a/src/x.h b/src/x.h
index 77d5dd02..09b4c75a 100644
--- a/src/x.h
+++ b/src/x.h
@@ -10,7 +10,20 @@
 #include "region.h"
 
 typedef struct session session_t;
-typedef struct winprop winprop_t;
+
+/// Structure representing Window property value.
+typedef struct winprop {
+  union {
+    void *ptr;
+    char *p8;
+    short *p16;
+    long *p32;
+    unsigned long *c32; // 32bit cardinal
+  };
+  unsigned long nitems;
+  xcb_atom_t type;
+  int format;
+} winprop_t;
 
 #define XCB_SYNCED_VOID(func, c, ...) xcb_request_check(c, func##_checked(c, __VA_ARGS__));
 #define XCB_SYNCED(func, c, ...) ({ \
@@ -54,6 +67,15 @@ winprop_t
 wid_get_prop_adv(const session_t *ps, Window w, Atom atom, long offset,
     long length, Atom rtype, int rformat);
 
+/**
+ * Wrapper of wid_get_prop_adv().
+ */
+static inline winprop_t
+wid_get_prop(const session_t *ps, Window wid, Atom atom, long length,
+    Atom rtype, int rformat) {
+  return wid_get_prop_adv(ps, wid, atom, 0L, length, rtype, rformat);
+}
+
 /**
  * Get the value of a type-<code>Window</code> property of a window.
  *