diff --git a/rmutil/Makefile b/rmutil/Makefile
index b203ed4..f29834d 100644
--- a/rmutil/Makefile
+++ b/rmutil/Makefile
@@ -3,7 +3,7 @@ ifndef RM_INCLUDE_DIR
 	RM_INCLUDE_DIR=../
 endif
 
-CFLAGS = -g -fPIC -lc -lm -O3 -std=gnu99 -I$(RM_INCLUDE_DIR)
+CFLAGS = -g -fPIC -lc -lm -O3 -std=gnu99 -I$(RM_INCLUDE_DIR) -Wall
 CC=gcc
 
 OBJS=util.o strings.o sds.o vector.o
@@ -17,7 +17,7 @@ librmutil.a: $(OBJS)
 	ar rcs $@ $^
 
 test_vector: test_vector.o vector.o
-	$(CC) -o test_vector vector.o test_vector.o -lc -O0
+	$(CC) -Wall -o test_vector vector.o test_vector.o -lc -O0
 	@(sh -c ./test_vector)
 
 	
diff --git a/rmutil/vector.c b/rmutil/vector.c
index f255844..ebd4668 100644
--- a/rmutil/vector.c
+++ b/rmutil/vector.c
@@ -45,7 +45,7 @@ int Vector_Resize(Vector *v, int newcap) {
     v->cap = newcap;
     
     v->data = realloc(v->data, v->cap*v->elemSize);
-    int offset = v->top*v->elemSize;
+    int offset = oldcap*v->elemSize;
     // put all zeros at the newly realloc'd part of the vector
     memset(v->data + offset, 0, v->cap*v->elemSize - offset);
     return v->cap;