diff --git a/getpid/Makefile b/getpid/Makefile
index 7f9b2d9..4a9367e 100644
--- a/getpid/Makefile
+++ b/getpid/Makefile
@@ -1,6 +1,7 @@
 NAME = getpid
 SRCDIR = ../rdtscbench
 CFLAGS = -lrt -lm
+LDFLAGS=-lm
 OBJ = $(SRCDIR)/rdtscbench.o $(NAME).o
 
 
@@ -9,7 +10,7 @@ all:
 	$(MAKE) -C . $(NAME)
 
 $(NAME): $(OBJ)
-	$(CC) $(CFLAGS) -o $(NAME) $(OBJ)
+	$(CC) $(CFLAGS) -o $(NAME) $(OBJ) $(LDFLAGS)
 
 $(SRCDIR)/rdtscbench.o: $(SRCDIR)/rdtscbench.h $(SRCDIR)/rdtscbench.c
 
diff --git a/matrix/Makefile b/matrix/Makefile
index e05fd71..0a72c35 100644
--- a/matrix/Makefile
+++ b/matrix/Makefile
@@ -1,6 +1,7 @@
 NAME = matrix
 SRCDIR = ../rdtscbench
 CFLAGS = -lrt -lm 
+LDFLAGS = -lm
 OBJ = $(SRCDIR)/rdtscbench.o $(NAME).o
 
 
@@ -9,7 +10,7 @@ all:
 	$(MAKE) -C . $(NAME)
 
 $(NAME): $(OBJ)
-	$(CC) $(CFLAGS) -o $(NAME) $(OBJ)
+	$(CC) $(CFLAGS) -o $(NAME) $(OBJ) $(LDFLAGS)
 
 $(SRCDIR)/rdtscbench.o: $(SRCDIR)/rdtscbench.h $(SRCDIR)/rdtscbench.c
 
diff --git a/moreExamples/Makefile b/moreExamples/Makefile
index 4b431bc..16682f9 100644
--- a/moreExamples/Makefile
+++ b/moreExamples/Makefile
@@ -1,6 +1,7 @@
 NAME = moreExamples
 SRCDIR = ../rdtscbench
 CFLAGS = -lrt -lm
+LDFLAGS = -lm
 OBJ = $(SRCDIR)/rdtscbench.o $(NAME).o
 
 
@@ -9,7 +10,7 @@ all:
 	$(MAKE) -C . $(NAME)
 
 $(NAME): $(OBJ)
-	$(CC) $(CFLAGS) -o $(NAME) $(OBJ)
+	$(CC) $(CFLAGS) -o $(NAME) $(OBJ) $(LDFLAGS)
 
 $(SRCDIR)/rdtscbench.o: $(SRCDIR)/rdtscbench.h $(SRCDIR)/rdtscbench.c
 
diff --git a/rdtscbench/Makefile b/rdtscbench/Makefile
index 4262536..eb3af63 100644
--- a/rdtscbench/Makefile
+++ b/rdtscbench/Makefile
@@ -1,11 +1,12 @@
-CFLAGS = -lrt -lm 
+CFLAGS = -lrt -lm
+LDFLAGS = -lm 
 
 all: gethz rdtscbench.o
 
 gethz:
 	./gethz.sh
 
-rdtscbench.o: rdtscbench.h rdtscbench.c
+rdtscbench.o: rdtscbench.h rdtscbench.c $(LDFLAGS)
 
 clean:
 	rm -f *~