diff --git a/src/Makefile b/src/Makefile
index 73a0fd3..78152fe 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,6 +1,9 @@
 all:
 	gcc -g -O0 -o pebblisp -D STANDALONE pebblisp.c tokens.c object.c env.c && ./tests.sh
 
+val:
+	gcc -g -O0 -o pebblisp -D STANDALONE pebblisp.c tokens.c object.c env.c && ./tests.sh -val
+
 debug:
 	gcc -g -O0 -o pebblisp -D STANDALONE -D DEBUG pebblisp.c tokens.c object.c env.c && ./tests.sh
 
diff --git a/src/tests.sh b/src/tests.sh
index 3267f16..5ba1a63 100755
--- a/src/tests.sh
+++ b/src/tests.sh
@@ -1,6 +1,11 @@
 #!/bin/bash
 PASSES=0
 FAILS=0
+VALGRIND=0
+
+if [ "$1" == "-val" ]; then
+        VALGRIND=1
+fi
 
 pass() {
         echo "$1 test PASSED"
@@ -13,7 +18,13 @@ fail() {
 }
 
 check() {
-        local output=$(./pebblisp "$2")
+        local output
+        if (($VALGRIND == 1)); then
+                local output=$(valgrind --leak-check=full ./pebblisp "$2")
+        else
+                local output=$(./pebblisp "$2")
+        fi
+
         if [ "$output" == "$3" ]; then
                 pass $1
         else
@@ -22,7 +33,8 @@ check() {
         fi
 }
 
-check "PlainRet" "5" "5"
+check "PlainRet" "10" "10"
+check "StrRetrn" "\"hey\"" "hey"
 echo ""
 check "Addition" "(+ 1093 102852)" "103945"
 check "Multiply" "(*1000 10000)" "10000000"
@@ -57,7 +69,12 @@ check "DemoFunc" "(spent 68)" "Tip: \$13.60"
 echo ""
 check "MultStmt" "(def yee (fn (a) (* 10 a))) (yee 5)" "50"
 check "DefinMap" "(def yee (fn (a) (* 10 a))) (map yee (5 10 2 (+ 12 0)))" "( 50 100 20 120 )"
-
+check "FbnciSeq" "(def fib (fn (a) \
+                    (if (< a 2) \
+                      a \
+                      (+ (fib (- a 1)) (fib (- a 2))) \
+                  ))) \
+                  (fib 20)" "6765"
 echo ""
 
 if [ "$FAILS" -ne "0" ]; then