--- fftw/api/fftw3.h
+++ fftw/api/fftw3.h
@@ -83,7 +83,7 @@ extern "C"
 #    define FFTW_EXTERN extern __declspec(dllimport)
 #  endif
 #else
-#  define FFTW_EXTERN extern
+#  define FFTW_EXTERN extern __attribute__ ((visibility("default")))
 #endif
 
 /* specify calling convention (Windows only) */
--- fftw/api/x77.h
+++ fftw/api/x77.h
@@ -65,5 +65,5 @@
 #if defined(FFTW_DLL) && (defined(_WIN32) || defined(__WIN32__))
 #  define FFTW_VOIDFUNC __declspec(dllexport) void
 #else
-#  define FFTW_VOIDFUNC void
+#  define FFTW_VOIDFUNC void __attribute__ ((visibility("default")))
 #endif
--- fftw/dft/dft.h
+++ fftw/dft/dft.h
@@ -54,7 +54,7 @@ typedef struct {
      dftapply apply;
 } plan_dft;
 
-plan *X(mkplan_dft)(size_t size, const plan_adt *adt, dftapply apply);
+IFFTW_EXTERN plan *X(mkplan_dft)(size_t size, const plan_adt *adt, dftapply apply);
 
 #define MKPLAN_DFT(type, adt, apply) \
   (type *)X(mkplan_dft)(sizeof(type), adt, apply)
--- fftw/kernel/ifftw.h
+++ fftw/kernel/ifftw.h
@@ -56,7 +56,7 @@ extern "C"
  && (defined(_WIN32) || defined(__WIN32__))
 #  define IFFTW_EXTERN extern __declspec(dllexport)
 #else
-#  define IFFTW_EXTERN extern
+#  define IFFTW_EXTERN extern __attribute__ ((visibility("default")))
 #endif
 
 /* determine precision and name-mangling scheme */
@@ -581,10 +581,10 @@ struct solver_s {
      int refcnt;
 };
 
-solver *X(mksolver)(size_t size, const solver_adt *adt);
+IFFTW_EXTERN solver *X(mksolver)(size_t size, const solver_adt *adt);
 void X(solver_use)(solver *ego);
 void X(solver_destroy)(solver *ego);
-void X(solver_register)(planner *plnr, solver *s);
+IFFTW_EXTERN void X(solver_register)(planner *plnr, solver *s);
 
 /* shorthand */
 #define MKSOLVER(type, adt) (type *)X(mksolver)(sizeof(type), adt)
--- fftw/rdft/rdft.h
+++ fftw/rdft/rdft.h
@@ -67,7 +67,7 @@ typedef struct {
      rdftapply apply;
 } plan_rdft;
 
-plan *X(mkplan_rdft)(size_t size, const plan_adt *adt, rdftapply apply);
+IFFTW_EXTERN plan *X(mkplan_rdft)(size_t size, const plan_adt *adt, rdftapply apply);
 
 #define MKPLAN_RDFT(type, adt, apply) \
   (type *)X(mkplan_rdft)(sizeof(type), adt, apply)
@@ -148,7 +148,7 @@ typedef struct {
      rdft2apply apply;
 } plan_rdft2;
 
-plan *X(mkplan_rdft2)(size_t size, const plan_adt *adt, rdft2apply apply);
+IFFTW_EXTERN plan *X(mkplan_rdft2)(size_t size, const plan_adt *adt, rdft2apply apply);
 
 #define MKPLAN_RDFT2(type, adt, apply) \
   (type *)X(mkplan_rdft2)(sizeof(type), adt, apply)