diff --git a/src/Makefile b/src/Makefile
index f04b4c4..b8d4b19 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -83,15 +83,15 @@ libespeak_SOURCES = speak_lib.cpp compiledict.cpp dictionary.cpp intonation.cpp
 
 SRCS1=$(speak_SOURCES)
 OBJS1=$(patsubst %.cpp,%.o,$(SRCS1))
-LIBS1=-lstdc++ $(LIB_AUDIO) -lpthread $(EXTRA_LIBS)
+LIBS1=-lstdc++ -lm $(LIB_AUDIO) -lpthread $(EXTRA_LIBS)
 
 SRCS2=$(libespeak_SOURCES)
 OBJS2=$(patsubst %.cpp,x_%.o,$(SRCS2))
-LIBS2=-lstdc++ $(LIB_AUDIO) -lpthread
+LIBS2=-lstdc++ -lm $(LIB_AUDIO) -lpthread
 
 SRCS3 = espeak.cpp
 OBJS3=$(patsubst %.cpp,%.o,$(SRCS3))
-LIBS3=-lstdc++ -L . -lespeak
+LIBS3=-lstdc++ -lm -L . -lespeak
 
 CXXFLAGS=-O2