diff --git a/api/apiplan.c b/api/apiplan.c
index 014fd4d5b..34fe27312 100644
--- a/api/apiplan.c
+++ b/api/apiplan.c
@@ -22,12 +22,15 @@
 
 static X(before_planner_hook_t) before_planner_hook = 0;
 static X(after_planner_hook_t) after_planner_hook = 0;
+static void *planner_hook_arg = 0;
 
 void X(set_planner_hooks)(X(before_planner_hook_t) before,
-                          X(after_planner_hook_t) after)
+                          X(after_planner_hook_t) after,
+                          void *arg)
 {
      before_planner_hook = before;
      after_planner_hook = after;
+     planner_hook_arg = arg;
 }
 
 static plan *mkplan0(planner *plnr, unsigned flags,
@@ -99,7 +102,7 @@ apiplan *X(mkapiplan)(int sign, unsigned flags, problem *prb)
      double pcost = 0;
      
      if (before_planner_hook)
-          before_planner_hook();
+          before_planner_hook(planner_hook_arg);
      
      plnr = X(the_planner)();
 
@@ -175,7 +178,7 @@ apiplan *X(mkapiplan)(int sign, unsigned flags, problem *prb)
 #endif
 
      if (after_planner_hook)
-          after_planner_hook();
+          after_planner_hook(planner_hook_arg);
      
      return p;
 }
diff --git a/api/fftw3.h b/api/fftw3.h
index 90221e407..e6a28240b 100644
--- a/api/fftw3.h
+++ b/api/fftw3.h
@@ -107,8 +107,8 @@ struct fftw_iodim64_do_not_use_me {
 
 typedef void (*fftw_write_char_func_do_not_use_me)(char c, void *);
 typedef int (*fftw_read_char_func_do_not_use_me)(void *);
-typedef void (*fftw_before_planner_hook_do_not_use_me)(void);
-typedef void (*fftw_after_planner_hook_do_not_use_me)(void);
+typedef void (*fftw_before_planner_hook_do_not_use_me)(void *arg);
+typedef void (*fftw_after_planner_hook_do_not_use_me)(void *arg);
 
 /*
   huge second-order macro that defines prototypes for all API
@@ -136,9 +136,10 @@ typedef fftw_before_planner_hook_do_not_use_me X(before_planner_hook_t);   \
 typedef fftw_after_planner_hook_do_not_use_me X(after_planner_hook_t);     \
                                                                            \
 FFTW_EXTERN void X(set_planner_hooks)(X(before_planner_hook_t) before,     \
-                                      X(after_planner_hook_t) after);      \
-									   \
-FFTW_EXTERN void X(execute)(const X(plan) p);				   \
+                                      X(after_planner_hook_t) after,       \
+                                      void *arg);                          \
+                                                                           \
+FFTW_EXTERN void X(execute)(const X(plan) p);                              \
 									   \
 FFTW_EXTERN X(plan) X(plan_dft)(int rank, const int *n,			   \
 		    C *in, C *out, int sign, unsigned flags);		   \
diff --git a/tests/fftw-bench.c b/tests/fftw-bench.c
index fe9c29d5e..bbf4c1b70 100644
--- a/tests/fftw-bench.c
+++ b/tests/fftw-bench.c
@@ -198,13 +198,15 @@ int can_do(bench_problem *p)
 
 static int before_planner_hook_called = 0;
 static int after_planner_hook_called = 0;
-static void before_planner_hook(void)
+static void before_planner_hook(void *arg)
 {
      before_planner_hook_called = 1;
+     BENCH_ASSERT(arg == &before_planner_hook_called);
 }
-static void after_planner_hook(void)
+static void after_planner_hook(void *arg)
 {
      after_planner_hook_called = 1;
+     BENCH_ASSERT(arg == &before_planner_hook_called);
 }
 
 void setup(bench_problem *p)
@@ -235,7 +237,7 @@ void setup(bench_problem *p)
 #endif
 
      if (setup_hooks)
-          FFTW(set_planner_hooks(before_planner_hook, after_planner_hook));
+          FFTW(set_planner_hooks(before_planner_hook, after_planner_hook, &before_planner_hook_called));
           
      before_planner_hook_called = 0;
      after_planner_hook_called = 0;
@@ -250,7 +252,7 @@ void setup(bench_problem *p)
      BENCH_ASSERT(setup_hooks == after_planner_hook_called);
 
      /* do something different with hooks next time */
-     FFTW(set_planner_hooks(0, 0));
+     FFTW(set_planner_hooks(0, 0, 0));
      setup_hooks = 1 - setup_hooks;
      
      {