diff --git a/alsamixer/Makefile.am b/alsamixer/Makefile.am
index 259b29e..249e8f8 100644
--- a/alsamixer/Makefile.am
+++ b/alsamixer/Makefile.am
@@ -1,4 +1,4 @@
-AM_CFLAGS = @CURSES_CFLAGS@ -DCURSESINC="@CURSESINC@"
+AM_CFLAGS = -D_GNU_SOURCE @CURSES_CFLAGS@ -DCURSESINC="@CURSESINC@"
 LDADD = @CURSESLIB@
 
 bin_PROGRAMS = alsamixer
diff --git a/alsamixer/volume_mapping.c b/alsamixer/volume_mapping.c
index 94bd0fe..48cfbe2 100644
--- a/alsamixer/volume_mapping.c
+++ b/alsamixer/volume_mapping.c
@@ -36,11 +36,6 @@
 #include <stdbool.h>
 #include "volume_mapping.h"
 
-#ifdef __UCLIBC__
-/* 10^x = 10^(log e^x) = (e^x)^log10 = e^(x * log 10) */
-#define exp10(x) (exp((x) * log(10)))
-#endif /* __UCLIBC__ */
-
 #define MAX_LINEAR_DB_SCALE	24
 
 static inline bool use_linear_dB_scale(long dBmin, long dBmax)