diff --git a/src/common.h b/src/common.h
index fd6273e..2b75ff7 100644
--- a/src/common.h
+++ b/src/common.h
@@ -1475,7 +1475,7 @@ timespec_subtract(struct timespec *result,
 /**
  * Get current time in struct timeval.
  */
-static inline struct timeval __attribute__((const))
+static inline struct timeval
 get_time_timeval(void) {
   struct timeval tv = { 0, 0 };
 
@@ -1490,7 +1490,7 @@ get_time_timeval(void) {
  *
  * Note its starting time is unspecified.
  */
-static inline struct timespec __attribute__((const))
+static inline struct timespec
 get_time_timespec(void) {
   struct timespec tm = { 0, 0 };
 
diff --git a/src/compton.h b/src/compton.h
index 2070aaf..0e27a75 100644
--- a/src/compton.h
+++ b/src/compton.h
@@ -500,7 +500,7 @@ update_reg_ignore_expire(session_t *ps, const win *w) {
 /**
  * Check whether a window has WM frames.
  */
-static inline bool __attribute__((const))
+static inline bool __attribute__((pure))
 win_has_frame(const win *w) {
   return w->a.border_width
     || w->frame_extents.top || w->frame_extents.left