diff --git a/tools/perf/ui/Build b/tools/perf/ui/Build
index 3aff83c3275f..6b6d7143a37b 100644
--- a/tools/perf/ui/Build
+++ b/tools/perf/ui/Build
@@ -10,5 +10,3 @@ CFLAGS_setup.o += -DLIBDIR="BUILD_STR($(LIBDIR))"
 perf-$(CONFIG_SLANG) += browser.o
 perf-$(CONFIG_SLANG) += browsers/
 perf-$(CONFIG_SLANG) += tui/
-
-CFLAGS_browser.o += -DENABLE_SLFUTURE_CONST
diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index 78fb01d6ad63..603d11283cbd 100644
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -57,12 +57,12 @@ void ui_browser__gotorc(struct ui_browser *browser, int y, int x)
 void ui_browser__write_nstring(struct ui_browser *browser __maybe_unused, const char *msg,
 			       unsigned int width)
 {
-	slsmg_write_nstring(msg, width);
+	SLsmg_write_nstring(msg, width);
 }
 
 void ui_browser__vprintf(struct ui_browser *browser __maybe_unused, const char *fmt, va_list args)
 {
-	slsmg_vprintf(fmt, args);
+	SLsmg_vprintf(fmt, args);
 }
 
 void ui_browser__printf(struct ui_browser *browser __maybe_unused, const char *fmt, ...)
@@ -808,6 +808,6 @@ void ui_browser__init(void)
 
 	while (ui_browser__colorsets[i].name) {
 		struct ui_browser_colorset *c = &ui_browser__colorsets[i++];
-		sltt_set_color(c->colorset, c->name, c->fg, c->bg);
+		SLtt_set_color(c->colorset, c->name, c->fg, c->bg);
 	}
 }
diff --git a/tools/perf/ui/browsers/Build b/tools/perf/ui/browsers/Build
index fdf86f7981ca..7a1d5ddaf688 100644
--- a/tools/perf/ui/browsers/Build
+++ b/tools/perf/ui/browsers/Build
@@ -4,8 +4,3 @@ perf-y += map.o
 perf-y += scripts.o
 perf-y += header.o
 perf-y += res_sample.o
-
-CFLAGS_annotate.o += -DENABLE_SLFUTURE_CONST
-CFLAGS_hists.o    += -DENABLE_SLFUTURE_CONST
-CFLAGS_map.o      += -DENABLE_SLFUTURE_CONST
-CFLAGS_scripts.o  += -DENABLE_SLFUTURE_CONST
diff --git a/tools/perf/ui/libslang.h b/tools/perf/ui/libslang.h
index 991e692b9b46..1dff3020e9d5 100644
--- a/tools/perf/ui/libslang.h
+++ b/tools/perf/ui/libslang.h
@@ -11,28 +11,16 @@
 #define HAVE_LONG_LONG __GLIBC_HAVE_LONG_LONG
 #endif
 
+/* Enable future slang's corrected function prototypes. */
+#define ENABLE_SLFUTURE_CONST 1
+#define ENABLE_SLFUTURE_VOID 1
+
 #ifdef HAVE_SLANG_INCLUDE_SUBDIR
 #include <slang/slang.h>
 #else
 #include <slang.h>
 #endif
 
-#if SLANG_VERSION < 20104
-#define slsmg_printf(msg, args...) \
-	SLsmg_printf((char *)(msg), ##args)
-#define slsmg_vprintf(msg, vargs) \
-	SLsmg_vprintf((char *)(msg), vargs)
-#define slsmg_write_nstring(msg, len) \
-	SLsmg_write_nstring((char *)(msg), len)
-#define sltt_set_color(obj, name, fg, bg) \
-	SLtt_set_color(obj,(char *)(name), (char *)(fg), (char *)(bg))
-#else
-#define slsmg_printf SLsmg_printf
-#define slsmg_vprintf SLsmg_vprintf
-#define slsmg_write_nstring SLsmg_write_nstring
-#define sltt_set_color SLtt_set_color
-#endif
-
 #define SL_KEY_UNTAB 0x1000
 
 #endif /* _PERF_UI_SLANG_H_ */
diff --git a/tools/perf/ui/tui/helpline.c b/tools/perf/ui/tui/helpline.c
index db4952f5990b..b39451314f43 100644
--- a/tools/perf/ui/tui/helpline.c
+++ b/tools/perf/ui/tui/helpline.c
@@ -22,7 +22,7 @@ static void tui_helpline__push(const char *msg)
 
 	SLsmg_gotorc(SLtt_Screen_Rows - 1, 0);
 	SLsmg_set_color(0);
-	SLsmg_write_nstring((char *)msg, SLtt_Screen_Cols);
+	SLsmg_write_nstring(msg, SLtt_Screen_Cols);
 	SLsmg_refresh();
 	strlcpy(ui_helpline__current, msg, sz);
 }
diff --git a/tools/perf/ui/tui/setup.c b/tools/perf/ui/tui/setup.c
index c1886aa184b3..605d9e175ea7 100644
--- a/tools/perf/ui/tui/setup.c
+++ b/tools/perf/ui/tui/setup.c
@@ -142,7 +142,7 @@ int ui__init(void)
 		goto out;
 	}
 
-	SLkp_define_keysym((char *)"^(kB)", SL_KEY_UNTAB);
+	SLkp_define_keysym("^(kB)", SL_KEY_UNTAB);
 
 	signal(SIGSEGV, ui__signal_backtrace);
 	signal(SIGFPE, ui__signal_backtrace);
diff --git a/tools/perf/ui/tui/util.c b/tools/perf/ui/tui/util.c
index 3c5174854ac8..e4d322ce0b54 100644
--- a/tools/perf/ui/tui/util.c
+++ b/tools/perf/ui/tui/util.c
@@ -106,7 +106,7 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
 	SLsmg_draw_box(y, x++, nr_lines, max_len);
 	if (title) {
 		SLsmg_gotorc(y, x + 1);
-		SLsmg_write_string((char *)title);
+		SLsmg_write_string(title);
 	}
 	SLsmg_gotorc(++y, x);
 	nr_lines -= 7;
@@ -117,12 +117,12 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
 	len = 5;
 	while (len--) {
 		SLsmg_gotorc(y + len - 1, x);
-		SLsmg_write_nstring((char *)" ", max_len);
+		SLsmg_write_nstring(" ", max_len);
 	}
 	SLsmg_draw_box(y++, x + 1, 3, max_len - 2);
 
 	SLsmg_gotorc(y + 3, x);
-	SLsmg_write_nstring((char *)exit_msg, max_len);
+	SLsmg_write_nstring(exit_msg, max_len);
 	SLsmg_refresh();
 
 	mutex_unlock(&ui__lock);
@@ -197,7 +197,7 @@ void __ui__info_window(const char *title, const char *text, const char *exit_msg
 	SLsmg_draw_box(y, x++, nr_lines, max_len);
 	if (title) {
 		SLsmg_gotorc(y, x + 1);
-		SLsmg_write_string((char *)title);
+		SLsmg_write_string(title);
 	}
 	SLsmg_gotorc(++y, x);
 	if (exit_msg)
@@ -207,9 +207,9 @@ void __ui__info_window(const char *title, const char *text, const char *exit_msg
 				   nr_lines, max_len, 1);
 	if (exit_msg) {
 		SLsmg_gotorc(y + nr_lines - 2, x);
-		SLsmg_write_nstring((char *)" ", max_len);
+		SLsmg_write_nstring(" ", max_len);
 		SLsmg_gotorc(y + nr_lines - 1, x);
-		SLsmg_write_nstring((char *)exit_msg, max_len);
+		SLsmg_write_nstring(exit_msg, max_len);
 	}
 }