diff --git a/Makefile b/Makefile
index 02fb069..558687b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -Wall -pedantic -ansi
+CFLAGS = -Wall -pedantic
 LDFLAGS = -lm
 BIN = graph.exe
 OBJ = errors.o lex.o main.o math_functions.o parser.o ps_graph.o tree.o
@@ -8,5 +8,5 @@ OBJ = errors.o lex.o main.o math_functions.o parser.o ps_graph.o tree.o
 	$(CC) -c $(CFLAGS) $< -o $@
 
 $(BIN): $(OBJ)
-	$(CC) $(LDFLAGS) $^ -o $@
+	$(CC) $^ -o $@ $(LDFLAGS)
 
diff --git a/Makefile.win b/Makefile.win
index 5ae7d9d..dfbea6f 100644
--- a/Makefile.win
+++ b/Makefile.win
@@ -1,5 +1,5 @@
 BIN = graph.exe
-OBJ = errors.o lex.o main.o parser.o ps_graph.o tree.o
+OBJ = errors.o lex.o main.o math_functions.o parser.o ps_graph.o tree.o
 
 .c.obj:
 	cl $< /c
diff --git a/ps_graph.c b/ps_graph.c
index 801f75e..14f6185 100644
--- a/ps_graph.c
+++ b/ps_graph.c
@@ -1,5 +1,6 @@
 #include "ps_graph.h"
 #include <math.h>
+#include <stdio.h>
 
 #define TEMP_BUF_SIZE  128